docs(requirements): add rows for the path-confinement and query-binding work

docs/requirements.md

@@ -399,6 +399,9 @@ Internal architecture, components, and application logic.
 | DR-207 | A pre-commit hook runs the "Before Committing" gates — frontend checks and tests, `cargo fmt`, clippy, the boundary tripwire and the traceability checks — so the gates are enforced at the commit rather than discovered in CI. The gates already exist and are already documented; what is missing is that nothing runs them, which makes compliance a matter of memory. The hook is the mechanism that makes the documented list actually binding | Tooling | - | Proposed |
 | DR-208 | Documentation link integrity is checked mechanically (`scripts/check-doc-links.sh`): every relative markdown link in every tracked `.md` must resolve to a file that exists on disk. This is a real defect class, not hygiene — the generated traceability matrix shipped ~2,800 dead file links because it was written to `docs/` while its hrefs were repo-root-relative, and nothing noticed for months because no check existed and nobody clicks 2,800 links. The check validates *paths*, deliberately not anchors or external URLs: anchor resolution needs a markdown renderer's slug rules and network checks make the gate flaky, so both are out of scope and stated as such in the script | Tooling | - | Done |
 | DR-209 | Library folders are excluded from music browsing **server-side, by folder id**, replacing a hardcoded frontend filter that dropped anything whose name contained "Podcasts". The name filter was wrong in three separate ways: it encoded a domain classification in the presentation layer, it matched on a title rather than on what an item *is* (so an album legitimately called "Podcasts" vanished while a podcast folder named anything else did not), and it applied only where someone had remembered to call it, so the same library was in scope on one screen and out of scope on the next. Excluded folder ids are stored as user configuration and applied by the repository layer to every music query — libraries, artists, albums, genres, search and the home rows — so scope is decided in one place and is the same everywhere | Repository | UR-076 | Proposed |
+| DR-210 | Thumbnail cache writes are confined to the cache directory. The filename was built from `item_id`, `image_type` and `tag`, but only `tag` was sanitised — and `Path::join` neither folds `..` nor keeps the base when handed an absolute path, so a value arriving verbatim from server JSON decided where a file landed. The tag's existing rule (non-alphanumerics become `_`) now applies to all three parts, and the resolved path is checked with `starts_with(cache_dir)` at the point of use. The database keeps the raw key and the resolved path, so lookups still match and pre-existing rows still resolve. Not exploitable as shipped — server URLs must be HTTPS and Android blocks cleartext, so the id comes from a server the user chose to trust — the value is making the write path consistent with how caller-supplied paths are handled elsewhere | Storage | UR-012 | Done |
+| DR-211 | Download paths are confined to the download root. `file_path` and `target_dir` reached `PathBuf::join` unchecked from the frontend, and `mark_download_completed` persisted a caller-supplied path later passed to `remove_file`. A correct sanitiser already existed and `download_item_and_start` used it, but `download_item` is itself a command accepting `file_path` raw, so the guard was bypassable rather than absent — the fix moves it inside instead of adding a second one. Sanitising is **per path component**: whole-string sanitising would rewrite `downloads/x.mp3` to `downloads_x.mp3` and relocate every existing download. Confinement happens after the join, since a join with an absolute second half discards the root | Downloads | UR-011 | Done |
+| DR-212 | Query and URL construction bind or encode their inputs. Three sites interpolated caller-supplied values directly: the offline `get_items` item-type filter built `IN ('a','b')` by string formatting, `build_get_items_endpoint` wrote `ParentId`/`IncludeItemTypes`/`SortBy`/`SortOrder` into a URL unencoded, and `player_set_volume` accepted NaN and out-of-range floats. Each is a *consistency* defect rather than a novel one — the same file already did it correctly a few lines away (parameter placeholders in `search`, `urlencoding::encode` for genres, `clamp` in every player backend). List separators stay unencoded and encoding is per element, because Jellyfin splits these parameters on the comma | Repository | UR-007, UR-065 | Done |
 | DR-198 | The webview runs under a real Content-Security-Policy, and the asset protocol is scoped to the one directory it still serves. `csp` was `null`, which disables CSP entirely: any script that reached the web layer — through a future `{@html}`, a dependency, or a devtools paste — would have inherited the whole IPC surface, and with it the user's session. `script-src 'self'` (Tauri injects a nonce for SvelteKit's inline bootstrap script at build time, so no `'unsafe-inline'` is needed) plus `object-src`/`frame-src 'none'` and `base-uri 'self'` is the part that is genuinely restrictive. `img-src`/`media-src`/`connect-src` cannot be: the Jellyfin origin is typed in by the user at run time and is commonly plain `http` on a LAN, so they allow `http:`/`https:` — a wide grant for *data*, but one that still bars `file:`, `filesystem:` and scripting schemes, and leaves `script-src` untouched. `style-src` keeps `'unsafe-inline'` because Svelte compiles `style="…"` attributes (including `app.html`'s `display: contents` wrapper) into markup; this is safe only while no `<style>` element survives into `index.html`, since a nonce there would make Tauri's injection outrank — and therefore void — `'unsafe-inline'`. `worker-src blob:` and `media-src blob:` are hls.js: it demuxes in a worker built from a blob and attaches MSE through `URL.createObjectURL`. `asset:` and `http://asset.localhost` are the same protocol under the two naming schemes `convertFileSrc` emits (custom scheme on Linux/macOS, `http` host on Windows/Android); `ipc:`/`http://ipc.localhost` is the invoke transport, which would otherwise be blocked by `connect-src`. A run-time CSP naming the server origin exactly was rejected: Tauri computes the header from immutable config when it serves the HTML, so it would mean rebuilding config and reloading the webview on every server change, for a policy the user can already point anywhere. The asset-protocol scope narrows from `$APPDATA/**` to `$APPDATA/thumbnails/**` — since DR-137 moved downloaded media to the loopback server, `imageCache` is the only `convertFileSrc` caller left, so the database and the encrypted-token fallback file no longer sit inside the grant | Security | UR-012, UR-071 | Done |
 
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@@ -689,6 +692,9 @@ Internal architecture, components, and application logic.
 | UT-201 | The logging facade gates by level: a message below the active level is not emitted at all, one at or above it reaches the sink, changing the level at run time changes what passes without touching the call sites, and a scoped logger tags its output with the subsystem | DR-204 | Proposed |
 | UT-202 | Generated traceability-matrix file links resolve from `docs/`: an emitted href, resolved against the directory `traceability.md` is written to, points at a file that exists on disk; the visible link text stays repo-root-relative; the `#Lnn` anchor survives; and a bare repo-root href — the regression that made every link 404 as `docs/<path>` — is rejected | DR-093 | Done |
 | UT-203 | Library folder exclusion filters by id, not by name: an excluded folder's items are absent from a music query, an item whose *title* merely contains an excluded folder's name is kept, and clearing the exclusion restores the items | DR-209 | Proposed |
+| UT-204 | Thumbnail cache writes stay inside the cache directory: a traversal-style and an absolute `item_id` both fail to produce a file outside it, a filename made only of already-safe characters is byte-identical to the one the previous code produced, and an odd id still round-trips through `get_cached_path` | DR-210 | Done |
+| UT-205 | Queued download paths cannot escape the download root — traversal, absolute and `..` forms are refused — while the four real path shapes the app builds, including the absolute one `download_series` produces, come back unchanged; and a completed download cannot register a file outside the root | DR-211 | Done |
+| UT-206 | The offline item-type filter is bound rather than interpolated (a value containing a quote and `OR 1=1` matches nothing instead of disabling the `WHERE`), `build_get_items_endpoint` percent-encodes its values while preserving the commas Jellyfin splits on, and volume normalisation clamps out-of-range input and maps NaN to a finite value | DR-212 | Done |
 | UT-200 | The stream a player could only restart is refused its retry: the handoff transcode answers yes to `player_retry_restarts_stream` while music, video and a downloaded episode answer no, and the Kotlin decision starts permissive, flips on a non-resumable load, and is restored by the next ordinary one | DR-203 | Done |
 
 ### Integration Tests