hermes - 💡(How to fix) Fix Dashboard: Spotify remote-control widget (Tier 1, Free-compatible) [1 participants]

Simpler companion to issue #15182 (Web Playback SDK widget). Ships faster, works for Free users, controls an existing Spotify client rather than becoming one.

What this is

A dashboard plugin showing a small transport bar — album art, track + artist, progress, play/pause/skip/volume. Polls spotify_playback get_state every few seconds for updates. Buttons call the existing Spotify tools directly (no SDK, no browser-as-device).

What this ISN'T

Not a Spotify client. No audio plays in the browser. This widget controls whatever Spotify is already running elsewhere — your phone, desktop app, Sonos, etc.

Issue #15182 (Web Playback SDK) IS a client. Strictly more capable but Premium-only and heavier.

Why both tiers make sense

• Tier 1 (this): ~200 LOC dashboard plugin, works on Spotify Free, useful to everyone, ships in a weekend.
• Tier 2 (#15182): ~400 LOC + SDK integration, Premium-only, useful to everyone with Premium who wants a self-contained in-browser player.

Users get strict upgrade when both ship. Tier 1's UI stays identical; Tier 2 adds 'this tab is a device' functionality underneath.

Requirements

• Dashboard plugin under plugins/ (new directory, follow plugins/example-dashboard/ / plugins/strike-freedom-cockpit/ pattern)
• Server-side poll: every 3-5s, dashboard backend calls spotify_playback get_state and pushes result over the existing dashboard WebSocket
• Client-side UI: album art, track title, artist, album, progress bar that ticks locally between updates
• Transport buttons wired to spotify_playback actions (play, pause, next, previous, seek via click on progress bar, volume slider)
• Device indicator: shows which device playback is on. Dropdown to transfer via spotify_devices transfer
• 'Not authed' state: when get_provider_auth_state('spotify') returns empty, widget shows a button linking to setup docs
• Play-action behavior matches the device resolution in issue #15611 (use spotify.default_device_name if set, otherwise let Spotify pick active device)
• No regression if the dashboard plugin isn't loaded — widget is opt-in per dashboard layout

Premium gating

On Free accounts, read-only actions still work (get_state, recently_played). Transport buttons should render as disabled or show a 'Premium required' tooltip rather than throwing 403s on click. Detect by checking the product field on /me once at load.

Open questions

• Polling interval: 3s feels responsive but racks up API calls. 5s is more polite. Start at 5s, drop to 2s when the widget has focus (document.hasFocus).
• Album art: cache client-side? Spotify's URLs are CDN-stable.
• Small-form factor: widget should look reasonable at 300px wide too. Progressive disclosure — album art only, then + track info, then + transport.

Scope estimate

• Backend: ~50 LOC (poll loop, WS push, tool dispatch for button clicks)
• Frontend: ~150 LOC (React/similar widget matching dashboard conventions)
• Total: ~200 LOC across the plugin

Acceptance

• Widget loads in dashboard, polls state
• Shows 'not authed' state gracefully when Spotify isn't configured
• Transport buttons work on Premium, degrade visibly on Free
• Progress bar ticks locally, doesn't jitter when poll arrives
• Transferring device via dropdown updates the state on next poll

Non-goals

• Playlist browsing (agent's job)
• Library management (agent's job)
• Queue management beyond 'show current queue'
• Multi-user device handling