docs: sync documentation with current codebase

- Update event formatter count 23 -> 28 (add ping, workflow_job, status, deployment, check_suite)
- Document Telegram support end-to-end (routes, /gh commands, richheader, secrets)
- Fix route schema to use targets array and group fields (owners, emoji)
- Correct KV/D1 storage layout (msg:*, i18n:*, D1 links/send_logs)
- Note GITHUB_APP_ID/GITHUB_PRIVATE_KEY are unused; drop legacy DISCORD_CHANNEL_ID/PORT/CONFIG_PATH
- Remove stale Docker deployment section
- Update color table, branch filter compatibility, admin API endpoints
- AGENTS.md: add Documentation section requiring doc updates after functional changes

docs/guide/getting-started.md

@@ -29,8 +29,6 @@ Edit `.dev.vars` with your actual values:
 
 ```bash
 GITHUB_WEBHOOK_SECRET=your-webhook-secret
-GITHUB_APP_ID=your-app-id
-GITHUB_PRIVATE_KEY="-----BEGIN PRIVATE KEY-----\n...\n-----END PRIVATE KEY-----"
 GITHUB_CLIENT_ID=your-client-id
 GITHUB_CLIENT_SECRET=your-client-secret
 DISCORD_TOKEN=your-bot-token
@@ -40,7 +38,7 @@ BASE_URL=http://localhost:8787
 ```
 
 ::: tip
-`GITHUB_PRIVATE_KEY` must be in **PKCS#8** format (`BEGIN PRIVATE KEY`). Convert a GitHub-issued PKCS#1 key with `openssl pkcs8 -nocrypt -in app.pem -out pkcs8.pem`. Target channels are set per route in the Web UI, so no `DISCORD_CHANNEL_ID` is needed. To enable `/gh` commands locally, copy the **Public Key** from the Developer Portal into `DISCORD_PUBLIC_KEY` and set the Interactions Endpoint URL to `http://localhost:8787/discord/interactions`.
+`GITHUB_APP_ID` / `GITHUB_PRIVATE_KEY` are not used by the code (the OAuth flow only needs the client ID/secret), so you can omit them. Target channels are set per route in the Web UI, so no `DISCORD_CHANNEL_ID` is needed. To enable `/gh` commands locally, copy the **Public Key** from the Developer Portal into `DISCORD_PUBLIC_KEY` and set the Interactions Endpoint URL to `http://localhost:8787/discord/interactions`.
 :::
 
 ::: warning