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/resources/skills/cad/SKILL.md

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+---
+name: cad
+description: Design parametric 3D models for 3D printing with OpenSCAD – from a description, a hand-drawn sketch or a photo. Renders STL/3MF and checks previews against the sketch.
+---
+# 3D models with OpenSCAD (for 3D printing)
+
+You design printable parts as **parametric OpenSCAD code**, render them with the `openscad`
+tool, look at the previews and refine until the part matches what the user wants.
+
+## 1. Understand the part
+- If the user attached a **sketch or photo**, describe what you see first: overall shape,
+  features (holes, slots, ribs, chamfers, text), views shown, and every **dimension written
+  on it** (with units). Hand-drawn sketches are not to scale – written numbers win over
+  proportions.
+- List what is missing for a printable part (overall size, wall thickness, hole diameters,
+  screw sizes, fit with other parts). Ask with `ask_user` in **one** round, offering sensible
+  defaults the user can just accept (e.g. "wall 2 mm, M3 holes 3.4 mm"). Don't ask about
+  things you can reasonably assume.
+
+## 2. Write the model
+Create `<name>.scad` in the project (or `cad/<name>.scad` if the project has other content):
+
+```openscad
+// <Part name> – <one-line purpose>
+// All dimensions in mm.
+
+/* [Main dimensions] */
+width  = 60;   // outer width (X)
+depth  = 40;   // outer depth (Y)
+height = 25;   // outer height (Z)
+wall   = 2;    // wall thickness
+
+/* [Holes] */
+hole_d = 3.4;  // M3 clearance
+
+/* [Quality] */
+$fn = 64;
+
+module body() { ... }
+module holes() { ... }
+
+difference() {
+  body();
+  holes();
+}
+```
+
+Rules:
+- **Every size is a named variable** at the top with a comment; group them with
+  `/* [Section] */` (shows up in OpenSCAD's customizer). No magic numbers in the geometry.
+- Small, named `module`s; `difference()` / `union()` / `hull()` / `minkowski()` (sparingly –
+  slow) / `linear_extrude()` / `rotate_extrude()`.
+- Model sits **on z = 0**, centred in X/Y unless the user wants otherwise.
+- Holes and cut-outs extend a little past the surface (`+0.01`/`2*eps`) to avoid
+  coplanar faces (z-fighting, non-manifold results).
+
+Printability (FDM defaults – adjust if the user says SLA/resin or names a printer/nozzle):
+- Minimum wall 1.2 mm (3 × 0.4 mm nozzle), better 2 mm for load-bearing parts.
+- Overhangs ≤ 45°; prefer chamfers over fillets on the bottom edge; bridges ≤ ~20 mm.
+- Fits: +0.2 mm clearance for sliding fits, +0.3–0.4 mm for loose fits; press fits −0.05 mm.
+  Horizontal holes come out slightly small – add 0.2 mm or use a teardrop shape.
+- Print orientation: flat largest face down; mention it in the summary.
+- Text: `linear_extrude(0.6) text(..., size ≥ 5, font="Liberation Sans:style=Bold")`.
+- Threads: use clearance holes plus heat-set inserts or nut traps instead of modelling threads,
+  unless the user asks for printed threads.
+
+## 3. Render and check
+- Run `openscad` with `formats: ["stl", "png"]` (add `"3mf"` for the final version) and the
+  views that show the important features (default iso, front, top).
+- Check the **bounding box** against the required dimensions and the **warnings** (a
+  non-manifold result must be fixed before printing).
+- Compare the previews with the sketch: proportions, feature positions, counts (holes, ribs),
+  orientation. Fix differences and render again. Two or three iterations are normal.
+- For variants, use `params` to override variables instead of copying the file.
+
+## 4. Deliver
+Summarise briefly:
+- Files: `.scad` (editable), `.stl` / `.3mf` (printable), previews.
+- Final dimensions (bounding box) and the key parameters the user may want to change.
+- Print hints: orientation, supports needed or not, suggested layer height/infill for the use.
+- Assumptions you made.
+The STL/3MF can be previewed in the file manager (3D view).