Rename the service to BugTrail ...

Bug + trail: the recorded trail of actions leading to the bug.
User-facing rename in the web panel shell, extension manifest/popup/
options, API title, i18n locales and README; Firefox id is now
bugtrail@gnexus.space. Internal @ltt/* package scopes unchanged.

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

Extension: picker, note composer, recorder + infra (Makefile, prod compose, README) ...

- MV3 extension for Chrome and Firefox: single codebase, per-entry IIFE
  builds (background / content / options), manifests generated per target
- Background service worker owns all networking (Bearer token from
  storage.local), captureVisibleTab (windowId!), recorder event buffer
  with offset_ms and auto-screenshots on clicks
- Content overlay in a closed shadow root (constructable stylesheets,
  kit CSS fetched from assets/style.css with /assets URL rewrite);
  PickerLayer, NoteComposer (autofocus, Ctrl+Enter submit),
  RecorderBar (step counter, note, stop)
- Options page: server URL, login, default project
- Recorder steps link screenshots by uploaded file id (server accepts
  attachment id or file id); environment/element JSONB serialized with
  mode="json" (datetime captured_at broke inserts)
- e2e harness: headless Chromium + extension, note + recording flows
- Makefile, docker-compose.prod.yml (caddy :8081 + static panel),
  deploy/Caddyfile, README (ru) with extension install and /assets notes

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