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>

site/dashboard.html

@@ -355,7 +355,7 @@
     <div class="footer">
       <div>Data refreshed every 6 hours by the metrics collector.</div>
       <div style="margin-top:0.5rem">
-        <a href="https://codeberg.org/johba/disinto">source</a>
+        <a href="http://localhost:3000/johba/disinto">source</a>
       </div>
     </div>
 
@@ -421,7 +421,7 @@
             var card = el('div', 'project');
             var nameDiv = el('div', 'name');
             var nameLink = document.createElement('a');
-            nameLink.href = 'https://codeberg.org/' + p.repo;
+            nameLink.href = 'http://localhost:3000/' + p.repo;
             nameLink.textContent = p.name;
             nameDiv.appendChild(nameLink);
             card.appendChild(nameDiv);