fix: Replace Codeberg dependency with local Forgejo instance (#611)

- Add setup_forge() to bin/disinto: provisions Forgejo via Docker,
  creates admin + bot users (dev-bot, review-bot), generates API
  tokens, creates repo, and pushes code — all automated
- Rename env vars: CODEBERG_TOKEN→FORGE_TOKEN, REVIEW_BOT_TOKEN→
  FORGE_REVIEW_TOKEN, CODEBERG_REPO→FORGE_REPO, CODEBERG_API→
  FORGE_API, CODEBERG_WEB→FORGE_WEB, CODEBERG_BOT_USERNAMES→
  FORGE_BOT_USERNAMES (with backwards-compat fallbacks)
- Rename API helpers: codeberg_api()→forge_api(), codeberg_api_all()
  →forge_api_all() (with compat aliases)
- Add forge_url field to project TOML; load-project.sh derives
  FORGE_API/FORGE_WEB from forge_url + repo
- Update parse_repo_slug() to accept any host URL, not just codeberg
- Forgejo data stored under ~/.disinto/forgejo/ (not in factory repo)
- Update all 58 files: agent scripts, formulas, docs, site HTML

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

action/AGENTS.md

@@ -25,7 +25,7 @@ issues labeled `action` that have no active tmux session, then spawns
 8. For human input: Claude sends a Matrix message and waits; the reply is injected into the session by `matrix_listener.sh`.
 
 **Environment variables consumed**:
-- `CODEBERG_TOKEN`, `CODEBERG_REPO`, `CODEBERG_API`, `PROJECT_NAME`, `CODEBERG_WEB`
+- `FORGE_TOKEN`, `FORGE_REPO`, `FORGE_API`, `PROJECT_NAME`, `FORGE_WEB`
 - `MATRIX_TOKEN`, `MATRIX_ROOM_ID`, `MATRIX_HOMESERVER` — Matrix notifications + human input
 - `ACTION_IDLE_TIMEOUT` — Max seconds before killing idle session (default 14400 = 4h)
 - `ACTION_MAX_LIFETIME` — Max total session wall-clock seconds (default 28800 = 8h); caps session independently of idle timeout