Download page: extension install guide for Chrome and Firefox ...

- public /download page (nav item «Расширение»): per-browser download
  buttons and step-by-step install instructions, setup (server URL is
  the panel's own origin) and hotkey reference, en/ru
- npm run package -w @ltt/extension zips dist/{chrome,firefox} into
  packages/web/public/ext (stable names, manifest at archive root so
  "Load unpacked" works right after unpacking)
- make ext / make prod always build fresh zips; deploy/.env.example
  seeds the release address bugtrail.gnexus.space

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

UI polish: fix black-on-dark leftovers, spacing, unstyled elements ...

- theme.css: design tokens mirroring kit's hardcoded Tokyo Night palette
  (--ltt-* + --color-* aliases used by @ltt/ui and the overlay)
- CompactSelect: kit GnSelect is a 54px/600px form control — compact
  variant for toolbar filters and the report status select
- ProjectPage: filters were blank (null modelValue matches no <option>)
  and huge; drop the floating GnTable caption chip
- AppShell: empty topbar chip is now a user identity + logout; remove
  unused props
- ReportPage/ProjectsPage/SettingsPage: kit .card is width:max-content/
  max-width:340px — cards fill their grid now; toolbar shows localized
  project count; PageHeader on settings
- ElementContext/EnvironmentInfo: row separators, dim labels, formatted
  CAPTURED date, selector rendered as a code chip
- ScreenshotViewer: optional labels prop (panel passes i18n strings)
- i18n: ru plural rules ("1 проект"), no hardcoded EN strings on
  auth pages; hide kit's "Forgot password?" stub link
- extension overlay: define --color-* vars on the shadow mount point
- Makefile: ext:watch/ext:test targets never parsed (colon in
  .PHONY/rules) — renamed to ext-watch/ext-test
- shot.mjs: screenshot harness for visual review of all pages

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>