Make attached launcher modal auto-resize to fit content instead of
using fixed dimensions. Move close button to top-right corner of the
window. Prevent launcher from being resizable in both modes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- Shrink standalone launcher from 1440x900 to 560x620 to match content
- Sync chooser card selection from persisted chooserMode on open
- Switch saved connections from double-click to single-click activation
- Add delete confirmation modal with Cancel default focus and danger button
- Add verification loading state (disabled button, empty-field guard)
- Add HTTP redirect hint for unreachable remotes on plain HTTP
- Show contextual error buttons (local vs remote failure paths)
- Add keyboard support: Arrow keys, Enter, Escape, focus trapping in modals
- Add ARIA roles and focus-visible outlines for chooser cards and connections
- Auto-focus first interactive element on view transitions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Replace the card-based mode picker with a two-tab interface:
- Local tab: hero layout with Launch button and auto-start checkbox
- Remote tab: saved connections list with single-click connect, Edit
  buttons, empty state, and Add Remote Connection action

Additional changes:
- Animate launcher window height transitions (180ms ease-out cubic)
- Enable dynamic height for standalone mode (not just attached sheets)
- Remove requirements box from remote form (verification enforces these)
- Update all back-navigation: remote form returns to Remote tab,
  error view routes to correct tab, saved connections returns to chooser
- Keyboard: Arrow Left/Right switches tabs, Up/Down navigates remote
  list, Enter activates focused connection
- Gitignore the chooser-variations mockup file

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The resize reporting was accidentally restricted to attached-only mode
during recent refactoring, breaking content-driven sizing for the
standalone loading screen.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Freshly created launcher windows stay hidden until the renderer reports
its actual content height, then show at the correct size. Eliminates
the visible flash from starting at the large initial dimensions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Use setContentSize instead of setBounds so the viewport matches the
reported content height exactly, and add a small buffer for macOS
sheet frame chrome. Also re-measure after two animation frames to
catch late layout shifts on first open.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>