feat: multi-format 3D viewer with large-file OBJ streaming, Z-up, projection/outline UI

Three.js viewer supporting glb/gltf/obj/fbx/dae/ifc/ply via both server (SSR)
and drag&drop (CSR) paths.

- Streaming OBJ parser (src/viewer/objStream.ts) for files past the V8 max
  string length (>~1GB text) that OBJLoader can't handle; indexed geometry,
  per-vertex color from MTL Kd, float64 recenter baked in.
- In-viewer float64 recenter (objRecenter.ts) for huge CAD/survey coordinates
  (~1e8) so float32 vertex buffers keep precision (no cracked faces).
- Z-up right-handed world; Y-up formats rotated on load.
- OBJ+MTL+texture drag&drop (LoadingManager URL-modifier maps dropped images).
- OrbitControls ground-plane panning (road/rail alignment workflow).
- UI: Zoom Fit, perspective/orthographic toggle, feature-edge outline.
- DoubleSide for CAD OBJ; PLY mesh + point-cloud support.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/commands/report.md

@@ -0,0 +1,17 @@
+---
+description: Append a status entry to PROGRESS.md summarizing what you just did.
+---
+
+Append a new entry to the TOP of the `## Work log` section in `PROGRESS.md`. Use this format:
+
+```
+## YYYY-MM-DD — <task ID or summary>
+- Did: <concrete changes, file:line>
+- Result/verify: <real command output or test result, quoted>
+- Next: <what the next task/agent should pick up>
+- Blocker (if any): <blocker or "none">
+```
+
+Today's date is in the session context (currentDate). Also flip the matching task row in `PLAN.md` to `done` (or `in_progress(@you)` if mid-task).
+
+Arguments: $ARGUMENTS — free text summary; if omitted, infer from recent work.