feat: non-blocking async I/O, auto-refresh tokens, YAML include detection, and new brand logo

[spelech]

Summary of Improvements

1. Non-Blocking Async File I/O

• Eliminates event loop blocking (ASYNC230) across backend views (BlocklistView, BlocklistAddView, AISettingsView, RebuildView, async_fetch_entities_data).
• Offloads all file reads and writes (gaGen_*.yaml, configuration.yaml, and *.json storage) to thread executor jobs via hass.async_add_executor_job.

2. Live Auth Token Refresh & Iframe Resilience

• Adds bidirectional postMessage synchronization between panel.js and app.js (HA_TOKEN_UPDATE and REQUEST_HA_TOKEN).
• Implements an authFetch wrapper in app.js that catches HTTP 401 Unauthorized responses, automatically requests a refreshed access token from the parent Home Assistant window, and retries the request seamlessly.
• Eliminates 30–60 minute session expiration errors when the dashboard is left open.

3. Missing YAML Include Guidance in UI

• Detects if configuration.yaml lacks an include statement for the generated YAML file.
• Displays an interactive alert banner in the restart confirmation dialog with the exact snippet required and a one-click Copy button.

4. Developer Experience & Code Quality

• Adds pyproject.toml configuring pytest (pythonpath = ['.']) and Ruff linting rules.
• Resolves all 61 Ruff linter errors/warnings (unused variables, unformatted imports, nested with statements, and mutable class attributes).
• Bumps integration manifest version to 1.8.0.
• All 338 unit and integration tests pass cleanly in ~1.2s.

5. Brand & App Logo Redesign

• Redesigns the brand icon and app logo combining the iconic Home Assistant house network graph with Google Assistant's official four-color palette (Blue #4285F4, Red #EA4335, Yellow #FBBC05, Green #34A853).
• Generates brand/logo.svg, high-resolution 1024x1024 PNGs (brand/logo.png, brand/icon.png), and web-optimized 512x512 asset (static/logo.png).
• Fully synchronized to local Home Assistant docker installation.