diff --git a/.gitea/workflows/publish-docs.yml b/.gitea/workflows/publish-docs.yml
new file mode 100644
index 00000000..bbc013b4
--- /dev/null
+++ b/.gitea/workflows/publish-docs.yml
@@ -0,0 +1,125 @@
+name: Publish Documentation
+
+# Renders the markdown docs (docs/*.md) into an mdBook site, builds the Rust
+# API reference with cargo doc, and force-pushes the combined output to the
+# orphan `gitea-pages` branch that the Gitea Pages server serves.
+#
+# The published matrix is regenerated during the build, so it is never stale.
+
+on:
+  push:
+    branches:
+      - master
+
+concurrency:
+  # Only one docs publish at a time; a newer push supersedes an in-flight run.
+  group: publish-docs
+  cancel-in-progress: true
+
+jobs:
+  publish-docs:
+    name: Build & publish docs to gitea-pages
+    runs-on: linux/amd64
+    container:
+      image: gitea.tourolle.paris/dtourolle/jellytau-builder:latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v1
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install
+
+      - name: Install mdBook
+        run: |
+          set -e
+          MDBOOK_VERSION=v0.4.40
+          URL="https://github.com/rust-lang/mdBook/releases/download/${MDBOOK_VERSION}/mdbook-${MDBOOK_VERSION}-x86_64-unknown-linux-gnu.tar.gz"
+          echo "⬇️  Downloading mdBook ${MDBOOK_VERSION}"
+          curl -fsSL "$URL" | tar -xz -C /usr/local/bin
+          mdbook --version
+
+      - name: Regenerate traceability matrix (keep published copy current)
+        run: bun run traces:markdown
+
+      - name: Assemble mdBook sources
+        run: |
+          set -e
+          # mdBook's src is docs/. Drop in the SUMMARY and the generated
+          # intro + API redirect pages (build artifacts, not committed).
+          cp docs-site/SUMMARY.md docs/SUMMARY.md
+
+          cat > docs/README.md <<'EOF'
+          # JellyTau Documentation
+
+          Cross-platform Jellyfin client — business logic in a Rust backend,
+          SvelteKit + TypeScript frontend, talking over Tauri v2 IPC.
+
+          - **[Requirements Specification](requirements.md)** — user, integration, and development requirements.
+          - **[Traceability Matrix](traceability.md)** — generated map from requirements to code (regenerated on every publish).
+          - **[Architecture](architecture/README.md)** — backend, frontend, data flow, platform backends.
+          - **[Rust API Reference](api/index.html)** — rustdoc for the `src-tauri` backend.
+
+          _This site is published automatically from `master` by the `publish-docs` CI job._
+          EOF
+
+          cat > docs/api-redirect.md <<'EOF'
+          # Rust API Reference
+
+          The full backend API reference is generated by `cargo doc` (rustdoc).
+
+          👉 **[Open the Rust API Reference](api/index.html)**
+          EOF
+
+      - name: Build mdBook site
+        run: mdbook build docs-site --dest-dir "$GITHUB_WORKSPACE/site"
+
+      - name: Build Rust API docs (cargo doc)
+        working-directory: src-tauri
+        # --no-deps keeps it to our own crate (fast, focused); document private
+        # items so internal modules/commands appear.
+        run: |
+          cargo doc --no-deps --document-private-items
+          # The backend modules/commands live in the LIB crate (jellytau_lib);
+          # the bin crate (jellytau) is a near-empty shim. Land on the lib.
+          echo '<meta http-equiv="refresh" content="0; url=jellytau_lib/index.html">' \
+            > target/doc/index.html
+
+      - name: Assemble published output
+        run: |
+          set -e
+          mkdir -p "$GITHUB_WORKSPACE/site/api"
+          cp -r src-tauri/target/doc/. "$GITHUB_WORKSPACE/site/api/"
+          # Disable Jekyll processing on the pages branch.
+          touch "$GITHUB_WORKSPACE/site/.nojekyll"
+          ls -la "$GITHUB_WORKSPACE/site"
+
+      - name: Push to gitea-pages branch
+        env:
+          # PAT preferred; falls back to the auto-provided token (same pattern
+          # as build-release.yml).
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          AUTO_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -e
+          TOKEN="${GITEA_TOKEN:-$AUTO_TOKEN}"
+          REPO="${GITHUB_REPOSITORY}"
+          HOST="$(echo "$GITHUB_SERVER_URL" | sed -E 's#^https?://##')"
+          REMOTE="https://oauth2:${TOKEN}@${HOST}/${REPO}.git"
+
+          cd "$GITHUB_WORKSPACE/site"
+          git init -q
+          git config user.name "gitea-actions"
+          git config user.email "actions@gitea.tourolle.paris"
+          git checkout -q -b gitea-pages
+          git add -A
+          git commit -q -m "docs: publish site from ${GITHUB_SHA::8}"
+          echo "🚀 Force-pushing to gitea-pages"
+          git push -f "$REMOTE" gitea-pages
diff --git a/.gitignore b/.gitignore
index 433fe992..bb917a4e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -58,3 +58,9 @@ android-keystore/
 
 # Local machine-specific Android NDK toolchain paths (do not commit)
 src-tauri/.cargo/config.toml
+
+# Docs site build artifacts (generated by the publish-docs CI job into docs/)
+/docs/SUMMARY.md
+/docs/README.md
+/docs/api-redirect.md
+/docs-site/book/
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 00000000..5d679c39
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,245 @@
+# JellyTau
+
+A cross-platform Jellyfin client. Business logic lives in a Rust backend
+(`src-tauri/`); a SvelteKit + TypeScript frontend (`src/`) handles presentation
+and talks to it over Tauri v2 IPC. Targets **Linux** (libmpv, WebKitGTK HTML5
+`<video>` for transcoded playback) and **Android** (ExoPlayer).
+
+Package manager is **bun**.
+
+## Build / Run / Test
+
+All routine tasks go through `package.json` scripts and helper scripts in
+`scripts/`:
+
+```bash
+bun install                  # install deps
+bun run dev                  # vite dev server (frontend)
+bun run tauri dev            # run the desktop app
+
+bun run check                # svelte-check (types)
+bun run test                 # vitest (frontend unit/integration)
+bun run test:rust            # cargo test (scripts/test-rust.sh)
+bun run test:all             # full suite (scripts/test-all.sh)
+bun run test:e2e             # webdriverio e2e
+
+# Android — canonical entry points (see scripts/):
+bun run android:build            # debug APK
+bun run android:build:release    # release APK
+bun run android:deploy           # install to connected device
+bun run android:dev              # build + deploy
+bun run android:logs             # logcat
+```
+
+CI runs on **Gitea Actions** (`.gitea/workflows/`), not GitHub. Use the `gh` CLI
+only against the mirror if one exists; the canonical remote is
+`gitea.tourolle.paris`.
+
+## Before Committing
+
+- Frontend: `bun run check` and `bun run test` must pass.
+- Rust: `cd src-tauri && cargo fmt` then `cargo clippy`, plus `bun run test:rust`.
+- **Traceability**: new requirement-implementing code must carry a `// TRACES:`
+  comment (see below).
+- **Android source edits**: edit `src-tauri/android/src` (the canonical tree),
+  then run `scripts/sync-android-sources.sh` to sync into the `gen/` tree.
+  Never edit the generated `gen/` sources directly.
+
+## Traceability (TRACES)
+
+This project practices requirement-driven development: code that implements a
+requirement is tagged with a `TRACES:` comment linking it to requirement IDs, and
+an extraction tool builds the traceability matrix. **When you add or change code
+that implements a requirement, add/update its TRACES comment.** Internal helpers
+and requirement-less code stay untraced.
+
+Format — `// TRACES: <URs> | <DRs> | <tests>`, e.g.:
+
+```rust
+/// TRACES: UR-005 | DR-001
+pub enum PlayerState { … }
+```
+```typescript
+// TRACES: UR-005, UR-026 | DR-029
+export function autoplayNextEpisode() { }
+```
+
+ID types: **UR** user requirement, **IR** integration, **DR** development, **JA**
+Jellyfin API, **UT** unit test, **IT** integration test. Requirements are defined
+in [docs/requirements.md](docs/requirements.md); the generated matrix is
+[docs/traceability.md](docs/traceability.md).
+
+Tooling:
+
+```bash
+bun run traces            # extract traces (default format)
+bun run traces:json       # JSON — e.g. | jq '.byType' or '.requirements."UR-005"'
+bun run traces:markdown   # regenerate docs/traceability.md
+git diff --name-only | xargs grep -L "TRACES:"   # find untraced changed files
+```
+
+**CI is Gitea Actions** (`.gitea/workflows/`, remote `gitea.tourolle.paris`), not
+GitHub. `traceability-check.yml` fails the build if coverage drops below
+**50%** (`MIN_THRESHOLD`); `build-and-test.yml` runs frontend + Rust tests and an
+Android `cargo check`. See [docs/traceability-ci.md](docs/traceability-ci.md) and
+[docs/traces-quick-ref.md](docs/traces-quick-ref.md).
+
+### Traces drive release notes
+
+Prefer traceability over raw commit subjects when writing release notes for
+[docs/release-checklist.md](docs/release-checklist.md). Raw `git log` subjects are
+noisy; the TRACES graph gives a semantic summary of *what capabilities* the
+release touched.
+
+```bash
+bun run release:notes                 # <latest tag>..HEAD
+bun run release:notes v0.0.15..HEAD   # explicit range
+```
+
+[scripts/release-notes.ts](scripts/release-notes.ts) resolves a commit range's
+changed files → their `TRACES:` IDs → descriptions in
+[docs/requirements.md](docs/requirements.md), then groups **UR** into *Features*
+and **DR/IR** into *Improvements* (deduped, so many commits touching one
+requirement collapse to one line). It also lists changed files that carry no
+TRACES so nothing is silently dropped — those still need a manual line. Treat the
+output as a reviewed draft, not a final changelog.
+
+## Architecture
+
+- **Rust backend** (`src-tauri/src/`) — all business logic: auth, catalog,
+  sessions, downloads, offline cache, playback control. Commands grouped by
+  domain in `src-tauri/src/commands/` (`auth.rs`, `catalog.rs`, `player/`,
+  `download/`, `offline.rs`, `sessions.rs`, …).
+- **Svelte frontend** (`src/`) — presentation only. Stores in
+  `src/lib/stores/`, API wrappers in `src/lib/api/`, components in
+  `src/lib/components/`.
+- **Playback layers** — Linux uses libmpv for direct playback and a WebKitGTK
+  HTML5 `<video>` element for HLS-transcoded (h264) streams; Android uses
+  ExoPlayer with a foreground media service + `MediaSessionCompat`.
+- **tauri-specta** generates TypeScript bindings and typed events from the Rust
+  command/event definitions (registered via the Builder in `src-tauri/src/lib.rs`).
+
+**Read the architecture docs before making structural changes** — they are the
+canonical, maintained source; this file only summarizes. See
+[docs/architecture/README.md](docs/architecture/README.md) and:
+
+| Doc | Contents |
+|-----|----------|
+| [01-rust-backend.md](docs/architecture/01-rust-backend.md) | Player/session state machines, playback mode, queue, commands |
+| [02-svelte-frontend.md](docs/architecture/02-svelte-frontend.md) | Stores, repository architecture, MiniPlayer, autoplay, nav guard |
+| [03-data-flow.md](docs/architecture/03-data-flow.md) | Cache-first query flow, playback initiation, mode transfer |
+| [04-type-sync-and-threading.md](docs/architecture/04-type-sync-and-threading.md) | **Rust↔TS type sync, the IPC camelCase convention + param table, locking** |
+| [05-platform-backends.md](docs/architecture/05-platform-backends.md) | MpvBackend (Linux), ExoPlayerBackend (Android), MediaSession, HTML5 adapter |
+| [06-downloads-and-offline.md](docs/architecture/06-downloads-and-offline.md) | Download manager/worker, smart cache, offline commands |
+| [07-connectivity.md](docs/architecture/07-connectivity.md) | HTTP retry, ConnectivityMonitor, reachability model |
+| [08-database-design.md](docs/architecture/08-database-design.md) | Tables, relationships, key queries |
+| [09-security.md](docs/architecture/09-security.md) | Token storage, secure storage, network security |
+
+Release process lives in [docs/release-checklist.md](docs/release-checklist.md)
+and [docs/build-release.md](docs/build-release.md).
+
+### Core principles (from the architecture docs)
+
+- **Playback state is one-directional.** The player (ExoPlayer on Android, MPV on
+  Linux, session poller in remote mode) is the **authoritative source** of state
+  — position, pause, seeking, rate, track changes. The Svelte UI, OS
+  `MediaSession`/lockscreen, and MPRIS are **consumers**; they reflect what the
+  player reports and never determine it.
+- **Unified player boundary.** UI controls playback *only* through the frontend
+  facade `src/lib/player/index.ts` (`playerController`) — never by calling
+  `commands.player*` directly. Webview HTML5 `<video>` reports its state back
+  into Rust via `src/lib/player/html5Adapter.ts` and the `player_report_*`
+  commands, so the controller stays the single source of truth in both native
+  and HTML5 modes.
+- **Reachability from real traffic.** Server online/offline is derived from the
+  outcome of actual repository requests (reported to `ConnectivityMonitor`), not
+  a side-channel poller. The `/System/Info/Public` probe runs *only while
+  offline*, as a recovery detector.
+- **Poison-tolerant locking.** Access shared `std::sync` state via the
+  `MutexSafe`/`RwLockSafe` helpers in `utils/lock.rs`, which recover a poisoned
+  lock instead of cascading a panic across the player.
+- **Graceful backend init.** If a native player backend fails to initialize, the
+  app falls back to a no-op backend and emits `backend-init-failed` rather than
+  crashing.
+
+## Conventions
+
+### Rust Backend
+
+- Use `#[tauri::command]` for all IPC handlers.
+- Prefer `async` commands for I/O-bound work.
+- Return `Result<T, String>` from commands (the established convention here).
+- Use `tauri::State<>` for shared state.
+- Group related commands in domain modules under `commands/`.
+- Use official Tauri plugins before writing custom native code.
+
+### Frontend
+
+- Use `invoke<T>()` from `@tauri-apps/api/core`, or the tauri-specta bindings.
+- Define TS types matching the Rust structs; prefer the generated bindings.
+- Handle IPC errors with try/catch.
+- Use `@tauri-apps/api/path` for paths (never hardcode).
+- Use `@tauri-apps/api/event` for backend→frontend events.
+
+### 🔴 IPC parameter naming (Tauri v2)
+
+The command **name** must match the Rust function name exactly
+(`invoke("player_play_queue", …)`). But **parameter names do NOT** — Tauri v2's
+`#[tauri::command]` macro auto-converts snake_case Rust params to **camelCase**
+on the frontend:
+
+```rust
+#[tauri::command]
+pub async fn cmd(repository_handle: String) { … }
+```
+```typescript
+await invoke("cmd", { repositoryHandle: "…" }); // camelCase, auto-converted
+```
+
+Nested struct fields need `#[serde(rename_all = "camelCase")]`; tagged unions use
+`#[serde(tag = "type")]` and both sides must match the tag. Note: tauri-specta
+tagged responses keep the Rust field names as-is (e.g. `new_url`, not `newUrl`).
+
+### Events
+
+- Backend events use **kebab-case** names (`download-event`, `search-event`).
+- Emit from Rust via `emit(...)`; consume on the frontend via
+  `@tauri-apps/api/event` or the tauri-specta typed event bindings.
+
+### Security
+
+- Declare minimum permissions in `src-tauri/capabilities/`.
+- Keep the CSP restrictive in `tauri.conf.json`.
+- Validate all inputs in Rust command handlers.
+- **Never read credentials** (tokens/keys from keyring, env, or stores) without
+  asking the user first.
+
+## Gotchas (hard-won)
+
+- **Never call sync/blocking APIs from event callbacks** that can re-enter the
+  player or hold a lock — it deadlocks. On Android, bind a locked
+  `AutoplayDecision` to a `let` *before* matching; a tokio `MutexGuard` held in
+  the `match` scrutinee deadlocks the `AdvanceToNext` arm.
+- **VideoPlayer native mode**: no lifecycle calls after an `await` in `onMount`
+  (it flips to HTML5 mode and breaks Android seek).
+- **Transcoded resume/seek**: `get_video_stream_url` must return the HLS
+  `master.m3u8`, not `stream.mp4`, or transcoded playback never starts.
+- **Downloads** cap at 3 concurrent; the backend pump auto-starts pending rows.
+  Don't loop `startDownload` from the frontend.
+- **Parallel Claude sessions**: the user may run concurrent sessions. Unexpected
+  file changes may be another session — check `git diff` before "repairing".
+
+## Testing
+
+```bash
+# Rust
+cd src-tauri && cargo test
+cd src-tauri && cargo test test_name        # single test
+
+# Frontend
+bun run test
+bun run test:coverage
+
+# Tauri IPC param-naming integration tests (guard the camelCase rule):
+bun run test -- tauriIntegration.test.ts
+```
diff --git a/docs-site/SUMMARY.md b/docs-site/SUMMARY.md
new file mode 100644
index 00000000..cefdd30c
--- /dev/null
+++ b/docs-site/SUMMARY.md
@@ -0,0 +1,39 @@
+# Summary
+
+[Introduction](README.md)
+
+# Requirements & Traceability
+
+- [Requirements Specification](requirements.md)
+- [Traceability Matrix](traceability.md)
+- [Traceability CI](traceability-ci.md)
+- [Traces Quick Reference](traces-quick-ref.md)
+
+# Architecture
+
+- [Overview](architecture/README.md)
+  - [Rust Backend](architecture/01-rust-backend.md)
+  - [Svelte Frontend](architecture/02-svelte-frontend.md)
+  - [Data Flow](architecture/03-data-flow.md)
+  - [Type Sync & Threading](architecture/04-type-sync-and-threading.md)
+  - [Platform Backends](architecture/05-platform-backends.md)
+  - [Downloads & Offline](architecture/06-downloads-and-offline.md)
+  - [Connectivity](architecture/07-connectivity.md)
+  - [Database Design](architecture/08-database-design.md)
+  - [Security](architecture/09-security.md)
+
+# UX & Specs
+
+- [UX Flows](ux-flows.md)
+- [Video Background Audio](specs/video-background-audio.md)
+
+# Build & Release
+
+- [Build & Release](build-release.md)
+- [Release Checklist](release-checklist.md)
+- [Docker](build/docker.md)
+- [Builder Image](build/build-builder-image.md)
+
+---
+
+[Rust API Reference (rustdoc)](api-redirect.md)
diff --git a/docs-site/book.toml b/docs-site/book.toml
new file mode 100644
index 00000000..e99ca1f2
--- /dev/null
+++ b/docs-site/book.toml
@@ -0,0 +1,25 @@
+# mdBook config for the published JellyTau documentation site.
+# The book's `src` is the repo `docs/` directory (see [build] below); this file
+# and SUMMARY.md live in docs-site/ to avoid cluttering docs/. The publish-docs
+# CI job copies SUMMARY.md into docs/ at build time, renders, and pushes the
+# result (plus the rustdoc API under /api/) to the orphan `gitea-pages` branch.
+[book]
+title = "JellyTau Documentation"
+description = "Requirements, traceability, and architecture for the JellyTau Jellyfin client."
+authors = ["Duncan Tourolle"]
+language = "en"
+# Sources live in the repo docs/ dir (one level up from this book root).
+src = "../docs"
+
+[output.html]
+default-theme = "navy"
+preferred-dark-theme = "navy"
+git-repository-url = "https://gitea.tourolle.paris/dtourolle/jellytau"
+edit-url-template = "https://gitea.tourolle.paris/dtourolle/jellytau/_edit/master/docs/{path}"
+
+[output.html.fold]
+enable = true
+level = 1
+
+[output.html.search]
+enable = true
diff --git a/docs/requirements.md b/docs/requirements.md
index 3f83bcd8..f350ed7e 100644
--- a/docs/requirements.md
+++ b/docs/requirements.md
@@ -50,6 +50,14 @@ For a narrative overview of the system design, see
 | UR-037 | Visually appealing video library with poster grids and metadata | High | Done |
 | UR-038 | Movie/show detail page with backdrop, ratings, and rich metadata | High | Done |
 | UR-039 | Navigate between main sections via bottom navigation bar | High | Done |
+| UR-040 | Keep a video's audio playing when the app is backgrounded or the screen is locked, stopping video decode until the app returns to the foreground (per-player toggle; Android) | Medium | Done (pending device verification) |
+| UR-041 | Continue watching *locally-playing video* in a floating picture-in-picture window when leaving the app (Android) — PiP applies to video only, never to audio playback, library/menu browsing, or remote/cast sessions | Medium | Done |
+| UR-042 | Authenticate to a server and manage the session lifecycle (connect, log in, Quick Connect, background session verification, re-authenticate, log out) | High | Done |
+| UR-043 | Automatically detect server reachability and switch between online and offline operation without user intervention | High | Done |
+| UR-044 | Pin downloaded media so it is protected from automatic cache eviction | Low | Done |
+| UR-045 | Predictively pre-cache likely-next media (queue lookahead and album affinity) within a storage budget | Low | Done |
+| UR-046 | Group multiple remote players into a synchronized playback group (LMS SyncGroups) | Low | Done |
+| UR-047 | Manage multiple Jellyfin servers (add, list, remove) and switch the active server/account | Medium | Planned (backend store done; switcher UI pending) |
 
 ---
 
@@ -85,6 +93,10 @@ External system integrations and platform-specific implementations.
 | IR-022 | Jellyfin API client for person/cast data | API | UR-035, UR-036 | Done |
 | IR-023 | Database schema for person/cast caching | Storage | UR-035, UR-036 | Done |
 | IR-024 | Jellyfin API client for home screen data (featured, continue watching) | API | UR-034 | Done |
+| IR-025 | Android background-audio handoff: WebView `<video>` → native ExoPlayer foreground service on background/lock, and back on foreground (audio continues, video decode stops) | Platform | UR-040 | Done (pending device verification) |
+| IR-026 | Android picture-in-picture: auto-enter on user-leave-hint via `enterPictureInPictureMode`, **only while a local video surface is actively rendering** (never for audio-only playback, menu/library browsing, or remote/cast sessions — enforced by the native `canEnterPip` guard, re-checked at leave time); aspect-ratio sizing; a play/pause RemoteAction that **reflects live player play/pause state** (updated whenever playback state changes, not only on button press); WebView hide/restore on mode change | Platform | UR-041 | Done |
+| IR-027 | Jellyfin `/System/Info/Public` reachability probe used as an offline→online recovery detector | API | UR-043 | Done |
+| IR-028 | Jellyfin/LMS SyncGroups API client (list, create, join, unsync, dissolve sync groups) | API | UR-046 | Done |
 
 ### 2.2 Jellyfin API Requirements
 
@@ -123,6 +135,7 @@ API endpoints and data contracts required for Jellyfin integration.
 | JA-029 | Get cast/crew for item (actors, directors) | Items | UR-035 | Done |
 | JA-030 | Get person details and filmography | Persons | UR-036 | Done |
 | JA-031 | Get items by person (actor/director filmography) | Items | UR-036 | Done |
+| JA-032 | Get audio-only stream URL for a video item (selected audio-stream index) | MediaInfo | UR-040 | Done |
 
 ### 2.3 Development Requirements
 
@@ -180,6 +193,16 @@ Internal architecture, components, and application logic.
 | DR-046 | Dedicated search page with input and results | UI | UR-039 | Done |
 | DR-047 | Next episode auto-play popup with configurable countdown and episode limit | Player | UR-023 | Done |
 | DR-048 | Video settings (auto-play toggle, countdown duration, episode limit) | Settings | UR-023, UR-026 | Done |
+| DR-051 | Background-audio toggle button in the video player controls (suppresses auto-PiP while enabled) | UI | UR-040 | Done (pending device verification) |
+| DR-052 | Background-audio handoff state machine: on background/lock tear down the WebView `<video>`/HLS decode and start native audio-only playback at the current position; on foreground return position and resume `<video>`; exactly one audio source active at every transition (no dual audio) | Player | UR-040 | Done (pending device verification) |
+| DR-053 | PictureInPictureManager: `canEnterPip` gate (local video surface actively rendering — false for audio, browsing, and remote/cast), aspect-ratio clamp, a RemoteAction play/pause receiver whose icon reflects live player state (refreshed on every playback-state change while in PiP, not only on button press), WebView hide/restore, surface re-fit on exit; plus the `AndroidPictureInPicture` JS bridge and the PiP button (shown only when PiP is supported) in the video player | UI | UR-041 | Done |
+| DR-054 | Auth manager and session lifecycle: connect-to-server, login, Quick Connect verification poll (start/stop), session get/set, background session verifier, re-authenticate, logout | Auth | UR-042 | Done |
+| DR-055 | ConnectivityMonitor deriving reachability from real repository traffic, with online/offline state, mark-reachable/unreachable reporting, and a probe-based recovery poller active only while offline | Connectivity | UR-043 | Done |
+| DR-056 | Download pinning (pin/unpin/is-pinned) that excludes an item from smart-cache eviction | Storage | UR-044 | Done |
+| DR-057 | Smart cache manager: album-affinity tracking, queue-lookahead pre-cache, storage-limit enforcement, config, stats, and recommendations | Storage | UR-045 | Done |
+| DR-058 | Remote sync-group control (LMS SyncGroups): list, create, unsync a player, dissolve a group | Player | UR-046 | Done |
+| DR-059 | Playback-mode transfer state machine: get/set current mode, transferring guard, transfer-to-remote / transfer-to-local, remote session status | Player | UR-010 | Done |
+| DR-060 | Multi-server store and active-account selection: save/get/delete server, save/get user, set/get active user (per-server), active-session resolution | Storage | UR-047 | Partial (store done; server-switcher UI pending) |
 
 ---
 
@@ -198,7 +221,7 @@ Internal architecture, components, and application logic.
 | UR-007 | IR-010 | DR-007, DR-008, DR-016 |
 | UR-008 | IR-010 | DR-007, DR-011 |
 | UR-009 | IR-009, IR-010, IR-011 | - |
-| UR-010 | IR-012, IR-021 | DR-037 |
+| UR-010 | IR-012, IR-021 | DR-037, DR-059 |
 | UR-011 | IR-013 | DR-003, DR-015, DR-018 |
 | UR-012 | IR-009, IR-014 | - |
 | UR-013 | IR-013 | DR-017 |
@@ -228,6 +251,14 @@ Internal architecture, components, and application logic.
 | UR-037 | IR-010 | DR-042 |
 | UR-038 | IR-010 | DR-043 |
 | UR-039 | - | DR-045, DR-046 |
+| UR-040 | IR-025 | DR-051, DR-052 |
+| UR-041 | IR-026 | DR-053 |
+| UR-042 | IR-009, IR-014 | DR-054 |
+| UR-043 | IR-027 | DR-055 |
+| UR-044 | - | DR-056 |
+| UR-045 | - | DR-057 |
+| UR-046 | IR-028 | DR-058 |
+| UR-047 | IR-013 | DR-060 |
 
 ---
 
@@ -295,6 +326,9 @@ Internal architecture, components, and application logic.
 | UT-056 | Playlist entry serialization | DR-019, JA-019 | Done |
 | UT-057 | Playlist Tauri command param naming (camelCase) | DR-019, JA-019, JA-020 | Done |
 | UT-058 | Playlist repository client methods | DR-019, JA-019, JA-020 | Done |
+| UT-059 | Audio-only stream URL builder for a video item (selected audio-stream index) | JA-032, DR-052 | Pending |
+| UT-060 | Background-audio handoff state machine (background→audio, foreground→video; no dual audio) | DR-052 | Pending |
+| UT-061 | Background-audio Tauri command param naming (camelCase) | DR-052 | Pending |
 
 ### Integration Tests
 
@@ -312,6 +346,7 @@ Internal architecture, components, and application logic.
 | IT-010 | Playback progress sync to Jellyfin | IR-015, UR-025 | Pending |
 | IT-011 | Resume playback from server position | IR-015, UR-019 | Pending |
 | IT-012 | Equalizer bands via libmpv | IR-020, UR-027 | Pending |
+| IT-013 | Background-audio handoff on Android: background/lock continues audio via native service and stops video decode; foreground resumes video at position | IR-025, UR-040 | Pending |
 
 ---
 
diff --git a/docs/specs/video-background-audio.md b/docs/specs/video-background-audio.md
new file mode 100644
index 00000000..b67ed1c8
--- /dev/null
+++ b/docs/specs/video-background-audio.md
@@ -0,0 +1,233 @@
+# Spec: Background audio for video playback (Android)
+
+**Status:** Draft
+**Scope:** Android only (v1). Linux noted as future work.
+**Branch base:** `android-picture-in-picture`
+**Requirements:** UR-040 → IR-025, JA-032, DR-051, DR-052 (see
+[requirements.md](../requirements.md)). Tests: UT-059, UT-060, UT-061, IT-013.
+
+## Summary
+
+Add a per-player toggle that lets the **audio** of a video keep playing when the
+app is backgrounded or the screen is locked, while **video decoding stops**.
+When the app returns to the foreground, video decoding resumes from the current
+audio position.
+
+This is the audio-first counterpart to the existing Picture-in-Picture feature
+(which keeps the *whole video* decoding in a floating window). The two are
+mutually exclusive: enabling background audio suppresses auto-PiP.
+
+## Motivation
+
+Users watching talk-heavy content (podcasts-as-video, lectures, music videos,
+concert films) want to lock the phone or switch apps and keep listening without
+draining battery on video decode or needing a visible floating window.
+
+## Background: how playback actually works here
+
+Two facts drive the entire design (verified in code, not assumed):
+
+1. **Video renders through the HTML5 `<video>` element in the WebView on both
+   platforms.** The native ExoPlayer *video* surface path is disabled — see the
+   INTERIM override in
+   [VideoPlayer.svelte](../../src/lib/components/player/VideoPlayer.svelte)
+   around the `playerPlayItem` response handling (`useHtml5Element` is forced
+   `true`, native backend is stopped). So "video decoding" == the WebView
+   `<video>` element, and the WebView is what Android suspends on background.
+
+2. **An Android WebView `<video>` element does not keep playing audio when the
+   app is backgrounded / locked.** The system throttles the WebView and media
+   pauses. Keeping audio alive in the background requires a **native foreground
+   media service**, which already exists for music:
+   [`JellyTauPlaybackService`](../../src-tauri/android/src/main/java/com/dtourolle/jellytau/player/JellyTauPlaybackService.kt)
+   +
+   [`JellyTauPlayer`](../../src-tauri/android/src/main/java/com/dtourolle/jellytau/player/JellyTauPlayer.kt)
+   (ExoPlayer) + `MediaSessionCompat`.
+
+**Therefore the design is a handoff**, not "keep the WebView alive": on
+background, stop the WebView `<video>` and start audio-only playback of the same
+item through the existing native ExoPlayer audio service; on foreground, hand
+back to the WebView `<video>`.
+
+This also aligns with the project's one-directional playback rule
+(`CLAUDE.md` → "Playback state is one-directional"): the currently-authoritative
+player (WebView element **or** native audio service) drives position; the UI and
+MediaSession consume it. The handoff is a change of *which* player is
+authoritative, and must transfer position cleanly.
+
+## User-facing behavior
+
+### The toggle
+
+- A toggle button in the video player controls (next to the existing PiP /
+  fullscreen buttons in
+  [VideoPlayer.svelte](../../src/lib/components/player/VideoPlayer.svelte)).
+- Icon: headphones / "audio-only" glyph. Two visual states (on/off).
+- **Visible only when** `isPipSupported()`-equivalent conditions hold — i.e.
+  Android with a native audio service available. Hidden on Linux in v1.
+- State is a UI preference on the player. Consider persisting the last choice
+  per user (see Open Questions) — v1 may default OFF each session.
+
+### When toggle is ON and the app goes to background / screen locks
+
+1. Auto-PiP is suppressed (see "Interaction with PiP").
+2. The WebView `<video>` is paused and its decode stopped (release the media
+   source so the decoder is freed, not merely `pause()`).
+3. Native audio-only playback of the same item starts at the current position,
+   through `JellyTauPlaybackService` (foreground notification + lockscreen
+   controls via the existing `MediaSessionCompat`).
+4. Lockscreen / notification shows the item with play/pause/seek, driven by the
+   native player (existing music behavior — reused, not rebuilt).
+
+### When toggle is ON and the app returns to foreground
+
+1. Native audio playback stops; its final position is captured.
+2. WebView `<video>` reloads/resumes at that position and continues as normal
+   audiovisual playback.
+3. Playback state (playing/paused) is preserved across the handoff.
+
+### When toggle is OFF (default)
+
+Current behavior is unchanged: backgrounding video auto-enters PiP
+(`onUserLeaveHint` → `PictureInPictureManager.enterPip`).
+
+## Interaction with PiP
+
+The toggle chooses one behavior or the other:
+
+- Toggle **ON** → call `AndroidPictureInPicture.setAutoEnterEnabled(false)` (the
+  bridge already exists,
+  [pictureInPicture.ts](../../src/lib/utils/pictureInPicture.ts) →
+  `setAutoEnterEnabled`). Background → audio handoff instead of PiP.
+- Toggle **OFF** → `setAutoEnterEnabled(true)`. Background → PiP (status quo).
+
+The frontend must also call `setAutoEnterEnabled(false)` on unmount if it left
+it enabled, and re-assert the correct value whenever the toggle changes, so a
+stale setting can't leak into the next player.
+
+> Note: `canEnterPip()` today requires `isPlayingVideo()` on the *native*
+> ExoPlayer, but video plays via the WebView, so native `isPlayingVideo()` is
+> false during normal playback. Confirm during implementation how auto-PiP is
+> actually triggering today (it may rely on a different signal), because the
+> background-audio handoff needs the same "is a local video active" signal to
+> know it should fire. **This is a load-bearing unknown — resolve it first
+> (Phase 0).**
+
+## Technical design
+
+### The audio-only stream
+
+Jellyfin can transcode/stream a video item as audio-only. Add a repository
+method (mirroring
+[`get_video_stream_url`](../../src-tauri/src/repository/online.rs) and
+[`get_audio_stream_url`](../../src-tauri/src/repository/mod.rs)) that returns an
+**audio-only stream URL for a video item** at a given audio-stream index — so
+the currently-selected audio track (`selectedAudioTrackIndex` in the player)
+carries over. Prefer direct-play of the audio stream where the container/codec
+allows; transcode to a broadly-supported audio codec otherwise.
+
+Position semantics must match between the WebView `<video>` timeline and the
+audio stream (account for the transcoded-HLS `seekOffset` model already in the
+player — see the `seekOffset` handling in `VideoPlayer.svelte`).
+
+### Backend command surface (Rust)
+
+New/extended `#[tauri::command]`s in `src-tauri/src/commands/player/` (follow the
+camelCase param rule and `Result<T, String>` convention):
+
+- `player_enter_background_audio(item_id, position_seconds, audio_stream_index)`
+  — stop WebView authority, start native audio-only playback at position; makes
+  the native player authoritative. Emits state via the existing player-event
+  channel so MediaSession/UI stay consumers.
+- `player_exit_background_audio() -> position_seconds` — stop native audio,
+  return final position for the WebView to resume from; restores WebView
+  authority.
+
+Reuse existing `player_play_*` / `player_stop` plumbing where possible rather
+than adding a parallel path.
+
+### Android native
+
+- Reuse `JellyTauPlaybackService` + `JellyTauPlayer` audio path
+  (`MediaSessionCompat`, foreground notification, audio-becoming-noisy, etc. —
+  all already implemented for music).
+- Add a bridge method (alongside `AndroidPictureInPicture`) or reuse an existing
+  one so the frontend can signal "prepare for background audio handoff" tied to
+  the Activity lifecycle (`onPause`/`onStop`/`onUserLeaveHint`).
+- On `onUserLeaveHint` / screen-off with background-audio enabled: **do not**
+  enter PiP; instead trigger the handoff command.
+- Respect the deadlock gotchas in `CLAUDE.md` (no sync/blocking calls from
+  player event callbacks; bind locked `AutoplayDecision` to a `let` before
+  matching).
+
+### Frontend (VideoPlayer.svelte)
+
+- Add toggle state + button. On change, call `setAutoEnterEnabled(!on)`.
+- Listen for Android lifecycle background/foreground signals (via a bridge event
+  or existing visibility hooks) and:
+  - background + ON → `player_enter_background_audio(...)`, pause + tear down the
+    `<video>`/HLS decode (reuse the existing HLS teardown sequence to avoid dual
+    audio).
+  - foreground + ON → `player_exit_background_audio()`, reload `<video>` at the
+    returned position, restore play/pause state.
+- **Follow the native-mode pitfall** (memory:
+  `videoplayer-native-mode-pitfalls`): no lifecycle calls after an `await` in
+  `onMount`. Keep the handoff logic out of that window.
+- Dual-audio is the key regression risk: at every handoff exactly one of
+  {WebView `<video>`, native ExoPlayer} produces audio. Tear the other down
+  *before* starting the next, mirroring the existing HLS cleanup discipline.
+
+## Phasing
+
+- **Phase 0 — De-risk (do first):**
+  - Confirm what actually triggers today's auto-PiP given video is on the
+    WebView (resolve the `canEnterPip`/`isPlayingVideo` question).
+  - Spike: obtain an audio-only stream URL for a video item and play it through
+    the native audio service; measure position accuracy and that WebView audio
+    is fully silenced (no dual audio).
+- **Phase 1 — Backend:** repository audio-only-URL method + the two player
+  commands + events.
+- **Phase 2 — Native:** lifecycle wiring, PiP suppression, handoff trigger.
+- **Phase 3 — Frontend:** toggle UI, lifecycle listeners, handoff calls,
+  teardown discipline.
+- **Phase 4 — Polish:** persist toggle preference, subtitle/audio-track
+  carry-over, edge cases (calls, headphone unplug, autoplay-next during
+  background audio).
+
+## Testing
+
+- Rust: unit tests for the audio-only URL builder and the two commands
+  (`cargo test`, `bun run test:rust`).
+- IPC param-naming integration tests for any new commands
+  (`bun run test -- tauriIntegration.test.ts`).
+- Frontend: `bun run check`, `bun run test`, plus a VideoPlayer logic test for
+  the handoff state machine (mirror the existing
+  `VideoPlayer.logic.test.ts`).
+- Manual on-device matrix:
+  - toggle ON: home button → audio continues, video stops decoding; return →
+    video resumes at position; playing/paused preserved.
+  - toggle ON: screen lock → audio continues; lockscreen controls work; unlock →
+    resumes.
+  - toggle OFF: background → PiP (unchanged).
+  - No dual audio at any transition. No audio leak after leaving the player.
+  - Transcoded (HEVC/10-bit) item — verify position with `seekOffset`.
+  - Autoplay-next fires correctly if an episode ends during background audio.
+
+## Open questions
+
+1. **Persist the toggle per user/series, or default OFF each session?**
+   (Recommend: remember last choice; series-level like the audio-track
+   preference is a nice-to-have.)
+2. **Autoplay-next during background audio** — should the next episode start as
+   audio-only and stay audio until foreground, or pause at episode end? (Recommend:
+   continue as audio-only.)
+3. **Subtitles** are irrelevant in audio-only mode but must restore on
+   foreground — confirm they survive the `<video>` teardown/reload.
+4. Exact **Android lifecycle signal** for "screen locked" vs "app backgrounded"
+   — `onUserLeaveHint` covers Home but not lock; may need a screen-off receiver.
+
+## Non-goals (v1)
+
+- Linux background audio (desktop windows keep running unfocused; low value).
+- Replacing or removing PiP — it stays as the toggle-OFF behavior.
+- Re-enabling the native ExoPlayer *video* surface path.
diff --git a/docs/ux-flows.md b/docs/ux-flows.md
index e64d69ea..c708f49f 100644
--- a/docs/ux-flows.md
+++ b/docs/ux-flows.md
@@ -690,24 +690,59 @@ flowchart TB
 └─────────────────────────────────────────┘
 ```
 
-### 9.2 Video Playback in Background
+### 9.2 Video Playback in Background (Android — PiP & Background Audio)
+
+Leaving the app while a **local video** is playing does not simply pause it.
+What happens depends on which background behaviour is active. The two are
+**mutually exclusive**, and both apply **only to locally-rendering video** —
+audio-only playback, library/menu browsing, and remote/cast sessions never
+trigger PiP (see decision gate below).
 
 ```mermaid
 flowchart TB
-    VideoPlaying[Video Playing] --> Background{User Action}
+    Leave[User leaves app<br/>Home / gesture / screen lock] --> Gate{Local video surface<br/>actively rendering?<br/>canEnterPip}
 
-    Background -->|Home Button| AutoPause[Automatically Pause]
-    Background -->|Screen Lock| AutoPause
+    Gate -->|No — audio, browsing,<br/>or remote/cast| Normal[App backgrounds normally<br/>audio, if any, continues via<br/>media notification &#40;§9.1&#41;]
 
-    AutoPause --> SaveProgress[Save Progress]
-    SaveProgress --> ShowNotification[Show Paused Notification:<br/>"Tap to Resume"]
+    Gate -->|Yes| Mode{Background mode armed?}
 
-    ShowNotification --> UserReturn{User Returns?}
+    Mode -->|Background-audio toggle ON<br/>UR-040| Handoff[Hand off to native audio service<br/>WebView &lt;video&gt; torn down,<br/>video decode stops, audio continues]
+    Mode -->|Default<br/>UR-041| PiP[Auto-enter Picture-in-Picture<br/>on onUserLeaveHint]
 
-    UserReturn -->|Tap Notification| ResumeVideo[Open App to Video Player]
-    UserReturn -->|Later| KeepPaused[Video Remains Paused]
+    PiP --> PiPWindow[Floating PiP window:<br/>- Video keeps rendering into surface<br/>- WebView hidden<br/>- Play/Pause RemoteAction<br/>  &#40;reflects live player state&#41;]
 
-    ResumeVideo --> AskResume[Resume from Saved Position]
+    PiPWindow --> PiPReturn{User action}
+    PiPReturn -->|Tap window| Restore[Return to full player<br/>WebView restored, surface re-fit]
+    PiPReturn -->|Close window| Stop[Playback stops]
+
+    Handoff --> Foreground[On return to foreground:<br/>resume WebView video at position]
+```
+
+**Key rules:**
+
+- **Video-only gate.** Auto-PiP is guarded by the native `canEnterPip` check
+  (local video surface actively rendering). Audio playback and menu/library
+  browsing background normally; remote/cast sessions render nothing locally, so
+  a PiP window would be an empty box and is refused. *(UR-041, IR-026)*
+- **Only one background behaviour at a time.** The background-audio toggle
+  (UR-040) disarms auto-PiP while it is on, so a video is either handed to the
+  audio service *or* floated in PiP, never both.
+- **PiP controls track the player.** The play/pause RemoteAction in the PiP
+  window reflects the live player state and updates on every playback-state
+  change, not only when the button is pressed. *(DR-053)*
+- **Non-disruptive transition.** ExoPlayer keeps rendering into the same
+  surface across enter/exit, so entering or leaving PiP never interrupts the
+  video; on exit the surface is re-fit to full-screen bounds. *(DR-053)*
+
+**PiP window (Android):**
+```
+        ┌───────────────────┐
+        │                   │
+        │   ▶ video frame   │
+        │                   │
+        │       [⏸]         │  ← play/pause RemoteAction
+        └───────────────────┘
+   sized to the video's aspect ratio
 ```
 
 ---
diff --git a/package.json b/package.json
index c7ffcc2c..7ae171ab 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,8 @@
     "tauri": "tauri",
     "traces": "bun run scripts/extract-traces.ts",
     "traces:json": "bun run scripts/extract-traces.ts --format json",
-    "traces:markdown": "bun run scripts/extract-traces.ts --format markdown > docs/traceability.md"
+    "traces:markdown": "bun run scripts/extract-traces.ts --format markdown > docs/traceability.md",
+    "release:notes": "bun run scripts/release-notes.ts"
   },
   "license": "MIT",
   "dependencies": {
diff --git a/scripts/release-notes.ts b/scripts/release-notes.ts
new file mode 100644
index 00000000..5bb8d58e
--- /dev/null
+++ b/scripts/release-notes.ts
@@ -0,0 +1,137 @@
+#!/usr/bin/env bun
+/**
+ * release-notes.ts — turn a commit range into capability-level release notes
+ * using the TRACES graph instead of raw commit subjects.
+ *
+ * Usage:
+ *   bun run scripts/release-notes.ts [<range>]
+ *   bun run scripts/release-notes.ts v0.0.15..HEAD
+ *
+ * With no argument it uses <latest tag>..HEAD (or the whole history if untagged).
+ *
+ * How it works:
+ *   1. `git diff --name-only <range>` → files the range changed.
+ *   2. Read each changed file's `TRACES:` comments → requirement IDs.
+ *   3. Resolve IDs to descriptions from docs/requirements.md.
+ *   4. Group: UR → Features, DR/IR → Improvements. Deduped, so many commits
+ *      touching one requirement collapse to one line.
+ *
+ * This is a drafting aid for docs/release-checklist.md — review the output,
+ * it does not invent descriptions for untraced changes (those are listed
+ * separately so nothing is silently dropped).
+ */
+
+import { execSync } from "node:child_process";
+import { readFileSync, existsSync } from "node:fs";
+
+const TRACE_RE = /TRACES:\s*([^\n*]+)/g;
+const ID_RE = /\b(UR|IR|DR|JA|UT|IT)-\d+\b/g;
+const REQ_ROW_RE = /^\|\s*((?:UR|IR|DR|JA)-\d+)\s*\|\s*([^|]+?)\s*\|/;
+
+function sh(cmd: string): string {
+  return execSync(cmd, { encoding: "utf8" }).trim();
+}
+
+function defaultRange(): string {
+  try {
+    const tag = sh("git describe --tags --abbrev=0");
+    return `${tag}..HEAD`;
+  } catch {
+    return ""; // no tags: fall through to whole-history diff
+  }
+}
+
+/** Map requirement ID → human description, parsed from docs/requirements.md. */
+function loadRequirementDescriptions(): Map<string, string> {
+  const map = new Map<string, string>();
+  const text = readFileSync("docs/requirements.md", "utf8");
+  for (const line of text.split("\n")) {
+    const m = line.match(REQ_ROW_RE);
+    // First definition wins: the descriptive tables come before the later
+    // cross-reference tables, whose cells hold linked IDs (or "-"), not prose.
+    if (m && !map.has(m[1])) map.set(m[1], m[2].trim());
+  }
+  return map;
+}
+
+function changedFiles(range: string): string[] {
+  const cmd = range
+    ? `git diff --name-only ${range}`
+    : "git ls-files"; // untagged repo: describe everything currently traced
+  return sh(cmd)
+    .split("\n")
+    .filter((f) => f && existsSync(f));
+}
+
+/** Collect requirement IDs referenced by TRACES comments in the given files. */
+function idsFromFiles(files: string[]): Set<string> {
+  const ids = new Set<string>();
+  for (const file of files) {
+    let content: string;
+    try {
+      content = readFileSync(file, "utf8");
+    } catch {
+      continue;
+    }
+    for (const trace of content.matchAll(TRACE_RE)) {
+      for (const id of trace[1].matchAll(ID_RE)) ids.add(id[0]);
+    }
+  }
+  return ids;
+}
+
+function main() {
+  const range = process.argv[2] ?? defaultRange();
+  const descriptions = loadRequirementDescriptions();
+  const files = changedFiles(range);
+  const ids = idsFromFiles(files);
+
+  const features: string[] = []; // UR
+  const improvements: string[] = []; // DR / IR
+  const unknown: string[] = []; // traced but not in requirements.md
+
+  for (const id of [...ids].sort()) {
+    const desc = descriptions.get(id);
+    if (id.startsWith("UT") || id.startsWith("IT")) continue; // tests aren't notes
+    if (!desc) {
+      if (!id.startsWith("UT") && !id.startsWith("IT")) unknown.push(id);
+      continue;
+    }
+    const line = `- ${desc} (${id})`;
+    if (id.startsWith("UR")) features.push(line);
+    else improvements.push(line);
+  }
+
+  const header = range || "(entire history — no tags found)";
+  const out: string[] = [`## Release notes — ${header}`, ""];
+
+  if (features.length) out.push("### ✨ Features", ...features, "");
+  if (improvements.length) out.push("### 🚀 Improvements", ...improvements, "");
+  if (unknown.length)
+    out.push(
+      "### ⚠️ Traced IDs missing from requirements.md",
+      ...unknown.map((id) => `- ${id}`),
+      "",
+    );
+
+  const untraced = files.filter((f) => {
+    try {
+      return !/TRACES:/.test(readFileSync(f, "utf8"));
+    } catch {
+      return false;
+    }
+  });
+  if (untraced.length)
+    out.push(
+      `### 📝 Changed files without TRACES (${untraced.length}) — review manually`,
+      ...untraced.map((f) => `- ${f}`),
+      "",
+    );
+
+  if (!features.length && !improvements.length)
+    out.push("_No traced requirements in this range._", "");
+
+  console.log(out.join("\n"));
+}
+
+main();