Add Gitea integration for agent to push branches and open pull requests

- Implemented `register-gitea-bot.sh` to provision Gitea access token.
- Updated `maintainer.py` to support Gitea API for push and PR operations.
- Modified `install.sh` to warn if Gitea token is not provisioned.
- Enhanced documentation in `README.md`, `CLAUDE.md`, and `architecture.md` to reflect new Gitea functionality.
- Added Gitea configuration to `config.example.json`.

CLAUDE.md

@@ -41,6 +41,13 @@ Claude Code, then relays/acts on the agent's JSON result.
   major/breaking ones to Matrix.
 - **Matrix**: bot `@maintainer-bot:semprini.me` DMs `@paul:semprini.me`. Escalations
   are numbered questions; the reply is fed back to the agent to carry out.
+- **Git/PRs**: when the agent changes tracked files it branches, pushes, and opens
+  a **pull request** on git.semprini.me (Gitea) as the `claude-code` user (never
+  commits to `main`); live remediation still happens immediately and directly.
+  The daemon injects claude-code's git identity + credential and the Gitea API
+  env into the headless agent (see `agent_git_env` / `GIT_PR_POLICY` in
+  `maintainer.py`); token provisioned by `register-gitea-bot.sh`. Empty
+  `gitea.token` disables the workflow.
 - **Autonomy** (`config.json` → `autonomy`): `full` (default) | `fix-only` |
   `notify`.
 
@@ -60,6 +67,7 @@ Claude Code, then relays/acts on the agent's JSON result.
 | `maintainer.py` | The daemon (stdlib only). |
 | `config.example.json` | Template — copy to `config.json`. |
 | `register-matrix-bot.sh` | Creates `@maintainer-bot` account + DM room; writes token to config. |
+| `register-gitea-bot.sh` | Mints the `claude-code` Gitea token (push + PRs); writes it to config. |
 | `install.sh` | Syntax-check, install unit, enable + start. |
 | `semprini-maintainer.service` | systemd unit (runs as `paul`). |
 | `docs/architecture.md` | Architecture decision record. |