Add web terminal, git credentials, OpenSCAD, review loops, automations

- Web terminal (PTY over WebSocket, xterm.js, sandboxed, reattach with replay)
- Per-user git credentials and commit identity (credential store in the user's home)
- OpenSCAD tool (STL/3MF + preview renders, bounding box) and cad skill; 3D model card
- Craft phase inferred from tool activity when the agent does not report it
- Configurable review loop per mode (rounds, reviewer model, criteria)
- Delete config and Markdown agents from the agent editor
- Automations: cron-scheduled agents from Markdown job files, schedule tool, page
- change_directory tool (only on the user's request)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.env.example

@@ -23,3 +23,6 @@ GEMINI_API_KEY=
 OPENCODE_API_KEY=
 FAL_KEY=
 OPENROUTER_API_KEY=
+
+# Time zone for automations (cron schedules) and timestamps, e.g. Europe/Berlin
+TZ=UTC