Add Assist, cameras, energy row, and local/Nabu Casa failover

[atoulmin]

Thanks for the original plugin — this builds on your bar/device work rather than replacing it.

This adds a few things we found ourselves wanting day to day: talk to Assist from the panel, show a few cameras and an energy summary, configure those from settings, and fail over from LAN to Nabu Casa when away from home.

Assist

• Text composer at the top of the panel (focused on open)
• Sends to assist_pipeline/run (intent stage) on the existing authenticated websocket
• Uses the preferred pipeline, or one chosen in Settings → Panel
• Follow-ups keep a conversation id; the thread clears after a minute of silence
• Greeting fades in on an empty thread; replies fade in and the list stays pinned
• IPC: omarchy-shell hass assist "…", hass assistClear

Cameras

• Configurable stills (Settings → Panel), refreshed only while the panel is open
• Snapshots go through the bridge to ~/.cache/omarchy/hass/cameras/ (no camera tokens in QML)
• Double-buffered 3:2 thumbs so refreshes do not blink
• Click a still to play the go2rtc main RTSP stream in a muted mpv window (omarchy-hass-camera); Esc or click quits
• Live preview hides the overlay panel so it is not covered by the layer-shell surface

Energy

• Optional charge / battery power / home load row
• Sensors are picked in Settings; built-in Tesla Energy ids are used only if those entities exist and nothing is configured

Connection

• Separate local and Nabu Casa remote URLs, one token
• Always tries local first; on a connection error, falls back to the remote URL
• Hero status is Connected locally or Connected via Nabu Casa instead of the old activity summary (1 on)
• Existing baseUrl configs migrate to the local URL

Settings

• New Panel tab: Assist pipeline, cameras (up to 6), battery charge, battery power, home load
• Connection tab has both addresses

Tests

• Bridge coverage for conversation, snapshots, and pipeline listing
• JS tests for Assist, cameras, Powerwall, connection labels, and config keys

Happy to split this if you would rather review Assist / cameras / connection as separate PRs.

[konradk]

Thank you for the PR, but there are too many changes in a single request. It's much easier to review and evaluate each change when changes are small and don't address multiple problems, so your idea to split them up is the right approach.

The proposed local URL setting was already implemented by another contributor, and I merged it a few minutes ago.