Memby v0.1.53: Android TV client plus gateway

Android TV client for Emby (Kotlin, Compose for TV) and the Memby gateway
(Go, Postgres, Redis) that fronts it.

Client:
- Setup, profiles, home rows, Media3 playback, system screensaver (Dream)
- Backend chosen at build time: gateway when memby.gatewayUrl is set,
  otherwise direct to Emby. Both paths stay working.
- Server-composed home rows, rendered verbatim so new row types ship
  without an app release
- Full-screen animated maintenance state, row engagement telemetry

Gateway:
- One request per TV screen; auth, caching, search and row shaping
- Library import from Emby into Postgres (manual, then hourly incremental)
- Recommendations from viewing history (recency-weighted genre affinity)
- Admin page for imports, an offline switch, and per-row analytics
- Video always direct-plays from Emby; only metadata passes through

Identity is com.ponzischeme89.memby throughout, replacing
com.mattcohen.embyclientsname. A changed applicationId installs as a new
app: TVs need a fresh sign-in and the old package uninstalled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/internal/store/schema.sql

@@ -0,0 +1,88 @@
+-- Gateway sessions: one row per signed-in TV.
+--
+-- token_hash is SHA-256 of the bearer token handed to the device, so a database dump
+-- does not hand over working gateway tokens. emby_token IS the live upstream token and
+-- is stored as-is: treat this volume as a secret store.
+CREATE TABLE IF NOT EXISTS sessions (
+    token_hash   BYTEA PRIMARY KEY,
+    emby_user_id TEXT        NOT NULL,
+    emby_token   TEXT        NOT NULL,
+    username     TEXT        NOT NULL,
+    server_id    TEXT        NOT NULL DEFAULT '',
+    device_id    TEXT        NOT NULL DEFAULT '',
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT now(),
+    last_seen_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS sessions_emby_user_idx ON sessions (emby_user_id);
+CREATE INDEX IF NOT EXISTS sessions_last_seen_idx ON sessions (last_seen_at);
+
+-- The imported library.
+--
+-- payload is Emby's item JSON verbatim, so rows served from here are byte-identical to
+-- rows served live. Deliberately holds NO per-user state: everything is imported with
+-- EnableUserData=false, because one household shares this table and watched/favourite
+-- flags are not shareable. Anything user-specific still comes from Emby live.
+CREATE TABLE IF NOT EXISTS library_items (
+    id               TEXT PRIMARY KEY,
+    type             TEXT        NOT NULL DEFAULT '',
+    name             TEXT        NOT NULL DEFAULT '',
+    series_id        TEXT        NOT NULL DEFAULT '',
+    series_name      TEXT        NOT NULL DEFAULT '',
+    production_year  INT,
+    community_rating REAL,
+    genres           TEXT[]      NOT NULL DEFAULT '{}',
+    studios          TEXT[]      NOT NULL DEFAULT '{}',
+    date_created     TIMESTAMPTZ,
+    search_text      TEXT        NOT NULL DEFAULT '',
+    payload          JSONB       NOT NULL,
+    synced_at        TIMESTAMPTZ NOT NULL DEFAULT now(),
+    -- 'simple' rather than 'english': film titles are proper nouns, and stemming
+    -- "Arrival" into "arriv" helps nobody.
+    search_tsv       tsvector GENERATED ALWAYS AS (to_tsvector('simple', search_text)) STORED
+);
+
+CREATE INDEX IF NOT EXISTS library_items_search_idx ON library_items USING GIN (search_tsv);
+CREATE INDEX IF NOT EXISTS library_items_genres_idx ON library_items USING GIN (genres);
+CREATE INDEX IF NOT EXISTS library_items_type_created_idx ON library_items (type, date_created DESC);
+CREATE INDEX IF NOT EXISTS library_items_synced_idx ON library_items (synced_at);
+
+-- One row per import, so the admin page can show what happened and when.
+CREATE TABLE IF NOT EXISTS sync_runs (
+    id             BIGSERIAL PRIMARY KEY,
+    kind           TEXT        NOT NULL,                    -- full | incremental
+    trigger        TEXT        NOT NULL DEFAULT 'schedule', -- schedule | manual | startup
+    status         TEXT        NOT NULL,                    -- running | success | failed
+    started_at     TIMESTAMPTZ NOT NULL DEFAULT now(),
+    finished_at    TIMESTAMPTZ,
+    items_seen     INT         NOT NULL DEFAULT 0,
+    items_upserted INT         NOT NULL DEFAULT 0,
+    items_removed  INT         NOT NULL DEFAULT 0,
+    error          TEXT        NOT NULL DEFAULT ''
+);
+
+CREATE INDEX IF NOT EXISTS sync_runs_started_idx ON sync_runs (started_at DESC);
+
+-- Small key/value store for operator switches (currently just maintenance mode). Kept in
+-- Postgres rather than memory so a restart cannot silently bring the app back up.
+CREATE TABLE IF NOT EXISTS app_settings (
+    key        TEXT PRIMARY KEY,
+    value      JSONB       NOT NULL,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- Row-level engagement. One row per reported event; aggregation happens at read time,
+-- which is fine at household scale and keeps the write path trivial.
+CREATE TABLE IF NOT EXISTS row_events (
+    id           BIGSERIAL PRIMARY KEY,
+    occurred_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
+    emby_user_id TEXT        NOT NULL,
+    row_id       TEXT        NOT NULL,
+    row_kind     TEXT        NOT NULL DEFAULT '',
+    event        TEXT        NOT NULL,                -- impression | focus | select
+    item_id      TEXT        NOT NULL DEFAULT '',
+    dwell_ms     INT         NOT NULL DEFAULT 0
+);
+
+CREATE INDEX IF NOT EXISTS row_events_time_idx ON row_events (occurred_at DESC);
+CREATE INDEX IF NOT EXISTS row_events_row_idx ON row_events (row_id, occurred_at DESC);