feat(self-hosted): server storage API in web-backend (#1898)

* feat(interfaces): add the server storage HTTP contract

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): read server storage configuration

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): open the server database and track revisions

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): playlist and user-state repositories

Playlist documents use the shared desktop row codec, so the server writes
the same rows. keepPayload upserts take the stored playlist/items/header
fields when the client leaves them out. Xtream user data lives in the
server-only server_user_state table, one JSON value per namespace and
playlist.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): storage error mapping and access token guard

Storage errors map to JSON status bodies and are logged by name and code
only. An optional bearer token guards every route except /, /health,
/config.js and /v1/instance, provider proxy routes included.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): serve the /v1 server storage API

/v1/instance is always public and reports whether server storage is on.
With storage, /v1/playlists serves whole documents with ETags and 304s,
accepts keepPayload upserts, and deletes playlists with their user state;
/v1/user-state and /v1/app-state store the rest. The proxy routes are
unchanged unless an access token is configured.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(web-backend): open server storage on start and close on shutdown

With IPTVNATOR_STORAGE=server, main.ts opens the database before it
listens and exits with a clear message when the data directory is not
writable. SIGTERM and SIGINT close the server and the database. The
native better-sqlite3 module stays outside the esbuild bundle.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web-backend): match weakened ETags on playlist reads

nginx weakens the ETag of a gzipped response, and clients send the weak
form back in If-None-Match. The route now compares tags weakly, as RFC 9110
requires for GET, so it answers 304 before reading the document.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* feat(docker): persist server storage on a volume

The image builds better-sqlite3 in a native stage per target platform,
enables server storage on the /data volume, and raises the nginx body
limit to 64 MB for /api with gzip for JSON. The compose file mounts a
named volume and documents the optional access token. The PWA does not
use the storage yet; docs say so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* test(web-backend): type the storage route responses

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web-backend): harden server storage reads, deletes and app state

- Metadata reads return the stored document without its payload fields,
  so fields that live only in the JSON survive a metadata round-trip.
- A conditional GET checks that the playlist exists before answering 304.
- Deleting a playlist and its user state commits in one transaction; the
  ETag moves only after the commit.
- Browser app state is stored under a client: prefix and the instance id
  is repaired when empty, so a client write cannot stop the backend.
- User-state buckets have no prototype, so ids like __proto__ round-trip.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* docs(self-hosted): keep the access token unset until the PWA sends it

Add the release note for the Docker server storage volume.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web-backend): bound shutdown and reject padded playlist ids

- SIGTERM closes idle connections at once and cuts the rest after five
  seconds, so a long provider download cannot keep the backend running.
- Playlist ids with surrounding whitespace are rejected: the row codec
  trims ids, so storage and ETags would track different keys.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web-backend): clear optional columns on whole-document upserts

The row codec maps empty values to undefined, which ON CONFLICT DO UPDATE
skips, so a cleared User-Agent, Referrer or credential kept its old column
value and came back on the next read. Server upserts now write NULL to
every replaceable column the document no longer sets.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(self-hosted): linear token parsing, no-store app state, longer start

- The access guard reads the Bearer token by string scanning instead of a
  regular expression that CodeQL flagged as polynomial on long whitespace.
- GET /v1/app-state/:key sends Cache-Control: no-store like the other
  state routes, so devices never reuse a stale value.
- The entrypoint waits up to IPTVNATOR_BACKEND_START_TIMEOUT (300 s) for
  /health, because the backend migrates its database before it listens.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(self-hosted): metadata reads skip payloads, redact JSON parse warnings

List playlist metadata from a server-only payload-free copy of each
document instead of running json_remove over every payload blob, and log
only the error name when a stored JSON value fails to parse, since the
parser's message quotes the stored text.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web-backend): copy carried-over panel clock into playlist metadata

When an upsert keeps the stored serverTimezone, build the metadata copy
from the saved payload so metadata and full reads agree.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

libs/shared/interfaces/src/index.ts

@@ -112,3 +112,4 @@ export * from './lib/xtream-connection-test';
 export * from './lib/portal-request-failure.util';
 
 export * from './lib/source-health';
+export * from './lib/server-storage.contract';

libs/shared/interfaces/src/lib/server-storage.contract.ts

@@ -0,0 +1,54 @@
+/**
+ * HTTP contract between the PWA and the self-hosted server storage. Routes
+ * live under `/v1` of the web backend (`/api/v1` behind the Docker nginx).
+ */
+export const SERVER_STORAGE_API_VERSION = 1;
+
+/** Xtream PWA user-data maps that the server stores per playlist id. */
+export const SERVER_USER_STATE_NAMESPACES = [
+    'xtream-favorites',
+    'xtream-recent-items',
+    'xtream-collection-items',
+    'xtream-playback-positions',
+] as const;
+
+export type ServerUserStateNamespace =
+    (typeof SERVER_USER_STATE_NAMESPACES)[number];
+
+export function isServerUserStateNamespace(
+    value: string
+): value is ServerUserStateNamespace {
+    return (SERVER_USER_STATE_NAMESPACES as readonly string[]).includes(value);
+}
+
+/**
+ * Document fields that carry an M3U payload. An upsert with
+ * `keepPayload=1` omits them and the server keeps the stored ones.
+ */
+export const SERVER_PAYLOAD_FIELDS = ['playlist', 'items', 'header'] as const;
+
+export interface ServerInstanceInfo {
+    readonly service: 'iptvnator';
+    readonly apiVersion: number;
+    /** Stable per database; `null` without server storage. */
+    readonly instanceId: string | null;
+    readonly storage: 'server' | 'none';
+    readonly auth: 'none' | 'token';
+}
+
+export interface ServerStorageStatusResponse {
+    readonly playlists: number;
+    readonly databaseBytes: number;
+    readonly databasePath: string;
+    readonly startedAt: string;
+}
+
+export interface ServerUserStateResponse {
+    readonly entries: Record<ServerUserStateNamespace, Record<string, unknown>>;
+}
+
+export interface ServerStorageErrorBody {
+    readonly message: string;
+    readonly status: number;
+    readonly code?: string;
+}