feat: witness Geometry Nodes zone pairing

[TMHSDigital]

Summary

• One example, gn-zone-iterate: Repeat Zone row + For Each Element tower. pair_with_output is load-bearing; asserts evaluated counts and per-iteration centers against closed forms, not tree structure.
• USD export_subdivision='BEST_MATCH' trap (silences evaluation_mode) taught in skills/depsgraph-and-evaluated-data and logged in docs/technical-audit.md. Zone pairing taught in skills/geometry-nodes-python.

Type

• feat — new skill / rule / snippet / template / example (minor bump)
• fix — correction to existing content or a broken contract (patch bump)
• docs / chore / ci / refactor — no release; release.yml still runs and should exit without a tag

Squash-merge subject: feat: witness Geometry Nodes zone pairing

Evidence

USD BEST_MATCH skill check — inspection-only of prior content, then this PR

No skill taught export_subdivision / BEST_MATCH before this branch. The trap lived only in examples/usd-export-evaluation-mode/. Added to skills/depsgraph-and-evaluated-data/SKILL.md (TESSELLATE vs BEST_MATCH, closed form 2 + 6 × 4^n, AI mistake) and docs/technical-audit.md. Zone pairing added to skills/geometry-nodes-python + the same audit log.

Check-only — live-run-proven

Windows .scratch/blender-5.2.1-windows-x64/blender.exe 5.2.1 LTS 9e2066aef7ef; .scratch/blender-4.5.11-windows-x64/blender.exe 4.5.11 LTS 4db51e9d1e1e.

No skips. Catalog row has no min_version. Zones are 4.3+.

Example	Binary	Exit	Marker
gn-zone-iterate	Win 5.2.1 + Win 4.5.11	0	Repeat 32/24, For Each 48/36, pairing=ok

Falsify (break, red, restore) — live-run-proven, both binaries

Count alone is not a sufficient witness. --no-offset still hits 32 verts with one X-center. Centers are the second axis. For Each main Geometry is a passthrough (6 verts) — a linked tree that does not iterate.

Flag	Exit	Result
(none)	0	32/24 and 48/36, pairing=ok
--unpair-repeat	3	Repeat 0/0
--unpair-foreach	5	For Each 0/0
--repeat-iterations 1	3	Repeat 16/12
--foreach-count 3	5	For Each 24/18
--foreach-main	5	For Each 6/0
--no-offset	4	32 verts, all on first X-center

Closed forms (cube = 8 verts / 6 faces): Repeat verts = 8 × (1 + N), N=3 → 32, X-centers at k × 1.2. For Each verts = 8 × P, P=6 → 48, Z-centers at i × 0.6 + 0.21.

Framing — live-run-proven (render path, Win 5.2.1)

fill y=0.833, margins left 0.222 / right 0.213 / bottom 0.078 / top 0.089. Camera (6.6, -9.3, 3.55), aim (0, 0, 1.50), lens 50.

Contact-sheet gate — live-run-proven luminance, inspection of composite

Pinned set: armature-bend / damped-track-aim / bmesh-gear. Not an asset-sheet subject.

Mean luma (Rec.709 / 255, 2×2 panels): armature-bend 0.2788, damped-track-aim 0.1722, bmesh-gear 0.3048, gn-zone-iterate 0.2112.

Stage darkness matches the pin set; wedge warmth on the back wall; brass row vs teal tower reads at thumbnail; saturation in family. Pass.

Composite: gn-zone-iterate

Generated HTML alts — inspection-only (read character-by-character after build_gallery.py)

docs/gallery/index.html:

• alt="gn-zone-iterate — Repeat Zone and For Each Element only iterate after pair_with_output."

Not truncated at a dotted API path. Detail witnesses callout matches gallery.json witnessesFix. Reverted a drive-by regen of docs/gallery/vse-cut-list/index.html.

Release-owned fields — do not hand-edit

VERSION, CHANGELOG.md, CLAUDE.md **Version:**, ROADMAP.md **Current:**, plugin.json "version". Left at 0.49.0.

Test plan

• blender-smoke 5.2 LTS: catalog row gn-zone-iterate PASS, no SKIP, zero-PASS job would be red
• blender-smoke 4.5 LTS: same
• validate-counts / validate-manifest green (48 examples)
• Socket Security not pending/failing
• After squash-merge: quote release.yml decision line; expect RELEASE (bump=minor) → v0.50.0

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