Rename MCP tools to mcp:server:tool format and restore human-readable names ...

- Core naming: mcp_server_tool → mcp:server:tool (colon-delimited)
- navi-web tools: search/view/request → web_search/web_view/http_request
- navi-3d tools: compile_scad/render_stl/lint_scad (unchanged names)
- Updated all profile configs, system prompts, docs, manuals, tests
- Added new lint_scad.md manual
- Fixed modeler_3d prompt stale references (scad_lint, model_3d, render_3d)
- All 240 tests pass

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Add 3D modeling profile with model_3d and render_3d tools ...

New profile:
- modeler_3d: 3D model design for 3D printing (OpenSCAD → STL)

New tools:
- model_3d: compile .scad → binary STL via OpenSCAD CLI
- render_3d: render PNG previews from STL (up to 3 views, 400×300)

Both tools return openscad_not_found error if OpenSCAD is not installed.

Docs:
- README.md: add modeler_3d to profile table
- docs/profiles.md: add modeler_3d to active profiles
- docs/tools.md: add model_3d and render_3d to builtin tools
- manuals/model_3d.md, manuals/render_3d.md: full usage manuals
- modeler_3d system_prompt.txt: OpenSCAD-first workflow with dedicated tools

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>