fix(templates): apply rotation as well as scale before grounding the origin

[TMHSDigital]

Closes #389.

Problem

ai-mesh-cleanup and the pipeline template applied transforms only when scale was non-identity. origin_to_base() shifts the geometry along local Z. So an imported glTF node with a rotation and unit scale, which is common, was grounded along the wrong axis and moved in world space.

Change

• scale_is_identity() is replaced by rot_scale_is_identity(), which checks the full 3×3 of matrix_basis, in both the skill and the template. Rotation is now applied too, so local Z equals world Z before grounding. The template's existing log line ("Applied object scale/rotation") is now accurate.
• origin_to_base() documents its precondition.
• Skill steps 3 and 4 explain the ordering, with the measured failure.

Evidence

Proven by live run (--factory-startup; binaries report 5.2.1 LTS and 4.5.11 LTS). The probe imports the real template helpers; the cube is rotated 90° on X at z=5 with unit scale:

Gate	World bbox before	World bbox after	Unchanged
New rot_scale_is_identity	[-1,-1,4]..[1,1,6]	[-1,-1,4]..[1,1,6] (origin z = 4.0, on the base)	True (both versions)
Old scale-only (falsifier)	[-1,-1,4]..[1,1,6]	[-1,-2,3]..[1,0,5]	False (both versions)

• An identity-transform object: the gate returns True, so there is no needless apply.
• The pipeline template on the CI fixture (make_pipeline_glb.py, unity preset, --collider convex) exits 0 on both versions: evaluated_tris=2208, LOD0 = 1024.

Not done: a rotated-input smoke fixture for the template. The CI fixture has no rotation, so CI exercises the new gate only on the identity path. The probe above is the rotated-case evidence.

🤖 Generated with Claude Code

[TMHSDigital]

CI evidence before merge: all checks pass ( 13 pass ). Blender Smoke on PR head: Blender 5.2.2 LTS / Blender 4.5.14 LTS. Summaries (happy path; falsifiers) per leg: 141 passed, 3 skipped, 0 failed;136 passed, 6 skipped, 0 failed;143 passed, 1 skipped, 0 failed;142 passed, 0 skipped, 0 failed;