docs: add mdBook docs-site, publish workflow, and release-notes tooling

Add a docs-site (mdBook) with a Gitea publish-docs workflow, a release-notes generator script (release:notes) that turns a commit range's TRACES into grouped notes, the background-audio feature spec, and CLAUDE.md. Ignore docs-site build artifacts.
2026-07-22 21:51:56 +02:00
parent 027054a200
commit 4e6ab017d4
10 changed files with 893 additions and 12 deletions
@@ -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 |

 ---

@@ -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.
@@ -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
 ```

 ---