feat(telegram): add Telegram support and unify config schema - #2

The translate-preview skill failed to capture CSS on sites that SSR with
localhost URLs (e.g. Next.js on Vercel). The fetch-based CSS inlining
silently failed and removed all <link rel="stylesheet"> tags, producing
unstyled preview HTML.

CSS capture:
- Primary: extract CSS from CSSOM (browser-loaded, URL-independent)
- Fallback: rewrite localhost URLs to page origin before fetching
- Absolutize relative url() in CSSOM CSS using each sheet's href
- Remove localhost preload/prefetch links from saved HTML

Block toggle (unify with twitter-render.js):
- Wrap block pairs in .tp-block container with data-state attribute
- Replace !important + body class + style.display hack with
  data-state driven CSS (no specificity conflicts with site CSS)
- Simplify interaction script: 3-line tpToggle vs getComputedStyle hack

CSP: revert PR#1's over-relaxation (http:, *, blob:) back to the
https:-only policy from ffb8356. The localhost errors were
ERR_CONNECTION_REFUSED, not CSP violations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…onfig

- Add @chat-adapter/telegram with long polling mode
- Introduce unified `config.home` (channel + channelId) replacing
  per-channel `channels.*.homeChannel` fields
- Add `config.notifications` for optional background job notifications
- Setup wizard: stepTelegram with BotFather guide, stepHome with
  Telegram polling UX (retry/manual fallback), mandatory home selection
- Remove stepNotifications from main wizard flow (still available via
  --step notifications)
- Full Telegram support across all subsystems: chat-setup, chat-handlers
  (session ID, isHomeChannel, extractRawChannelId), reply (postToChannel),
  admin-server (post_message, list_channels), cron delivery, bootstrap
  greeting, context-builder markdown guidance, finalize notifications
- Update SKILL.md templates to use 'home channel' terminology

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Upgrade all @chat-adapter/* and chat packages to ^4.20.0
- Replace heartbeat.notifications nested structure with flat
  heartbeat.desktop + top-level config.notifications
- Use z.enum(['discord','slack','telegram']) for home/notifications
  channel field (type-safe validation)
- Add legacy config auto-migration in io.ts (old homeChannel,
  old heartbeat.notifications, old notifications format)
- Add telegram.mode, telegram.respondInChannels to schema
- Add telegram to WorkspaceConfigSchema
- Update finalize.ts to use unified config.notifications
- Add telegram trigger to bootstrap.ts
- Add telegram to ReactionPlatformBehavior
- Fix Chat SDK 4.20 event.thread nullable in chat-handlers.ts
- Rewrite stepHeartbeatNotifications() for new config format

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- D-1: shouldRespondInChannel() now includes telegram adapter
  (was returning false, making respondInChannels ineffective)
- T-1: Replace notifications!.channel with ?.channel in catch handler
- D-2: Remove misplaced Slack JSDoc above Telegram interfaces
- R-3: Update comment to include Telegram in respondInChannels note

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Extract migrateLegacyConfig() and write back to config.json on first
load so old keys (homeChannel, heartbeat.notifications, old
notifications format) are cleaned up permanently.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…onfig

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…ng UX

- notifyBackgroundJob falls back to config.home when notifications unset
- deriveChannelSessionPrefix handles Telegram adapter
- pollForTelegramChat uses AbortSignal.timeout to prevent hang
- Telegram polling loop adds skip option for using other channel as home
- Chat ID manual input validates numeric format
- parseHomeValue guards against missing colon
- migrateLegacyConfig preserves homeChannel from disabled platforms
- printBanner shows Telegram connection status

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

QMD 1.1.6 added an exports field that only exposes ".", blocking
Node.js ESM resolution of ./dist/store.js and ./dist/mcp.js imports
used by serve.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>