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>

VISION.md

@@ -34,7 +34,7 @@ A solo founder sets the vision and defines quality gates. Disinto derives the ba
 ## Growth goals
 
 - **Attract developers** — the project should be easy to understand, easy to fork, easy to contribute to.
-- **Stars and forks** — measure traction through Codeberg/GitHub engagement.
+- **Stars and forks** — measure traction through forge/GitHub engagement.
 - **Contributors** — lower the barrier to entry. Good docs, clear architecture, working examples.
 - **Reference deployments** — showcase real projects built and operated by Disinto.
 - **Vault as differentiator** — the quality gate model (vision + vault) is what sets Disinto apart from generic CI/CD. Make it visible and easy to understand.