feat(prd-5): add dedicated claude-bot user for Forgejo

- Add bot_email action input for custom git commit email on Forgejo
- Update claude.yml to use CLAUDE_BOT_TOKEN with bot_id/bot_name/bot_email
- Update git-config.ts to use provided email over noreply format
- Add "Dedicated Bot User" setup guide to docs/forgejo.md
- Update CLAUDE.md with bot identity documentation

Infrastructure (done outside code):
- claude-bot user created (ID 48, non-admin, with avatar)
- Claude team with write access in all 12 orgs
- CLAUDE_BOT_TOKEN org-level secret in all 12 orgs

Progress: ~85% complete - pending E2E validation after merge

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

src/github/context.ts

@@ -94,6 +94,7 @@ type BaseContext = {
     sshSigningKey: string;
     botId: string;
     botName: string;
+    botEmail: string;
     allowedBots: string;
     allowedNonWriteUsers: string;
     trackProgress: boolean;
@@ -154,6 +155,7 @@ export function parseGitHubContext(): GitHubContext {
       sshSigningKey: process.env.SSH_SIGNING_KEY || "",
       botId: process.env.BOT_ID ?? String(CLAUDE_APP_BOT_ID),
       botName: process.env.BOT_NAME ?? CLAUDE_BOT_LOGIN,
+      botEmail: process.env.BOT_EMAIL ?? "",
       allowedBots: process.env.ALLOWED_BOTS ?? "",
       allowedNonWriteUsers: process.env.ALLOWED_NON_WRITE_USERS ?? "",
       trackProgress: process.env.TRACK_PROGRESS === "true",