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>

server/Cargo.toml

@@ -41,3 +41,5 @@ uuid = { version = "1", features = ["v4", "v7"] }
 p256 = { version = "0.14", features = ["ecdh", "ecdsa"] }
 hkdf = "0.13"
 aes-gcm = "0.11"
+pty-process = { version = "0.5.4", features = ["async"] }
+croner = "4.0.3"