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/docs/architecture.html

@@ -365,7 +365,7 @@
     <!-- Eight Agents -->
     <div class="section">
       <h2>Eight agents</h2>
-      <p>Each agent has a single responsibility. They communicate through git, the Codeberg API, and the filesystem.</p>
+      <p>Each agent has a single responsibility. They communicate through git, the forge API, and the filesystem.</p>
       <div class="agents-grid">
         <div class="agent-card">
           <div class="name">dev-agent</div>
@@ -480,7 +480,7 @@
         <p><strong>Bash scripts</strong> &mdash; every agent is a shell script. No compiled binaries, no runtimes to install.</p>
         <p><strong>Claude CLI</strong> &mdash; AI is invoked via <code>claude -p</code> (one-shot) or <code>claude</code> (persistent tmux sessions).</p>
         <p><strong>Cron</strong> &mdash; agents are triggered by cron jobs, not a daemon. Pull-based, not push-based.</p>
-        <p><strong>Codeberg + Woodpecker</strong> &mdash; git hosting and CI. All state lives in git and the issue tracker. No external databases.</p>
+        <p><strong>Forgejo + Woodpecker</strong> &mdash; git hosting and CI. All state lives in git and the issue tracker. No external databases.</p>
         <p><strong>Single VPS</strong> &mdash; runs on an 8 GB server. Flat cost, no scaling surprises.</p>
       </div>
     </div>
@@ -538,7 +538,7 @@ disinto/
     <div class="footer">
       <a href="/">&larr; disinto.ai</a> &middot;
       <a href="/docs/quickstart">Quickstart</a> &middot;
-      <a href="https://codeberg.org/johba/disinto">Source</a>
+      <a href="http://localhost:3000/johba/disinto">Source</a>
     </div>
 
   </div>