Reorganize docs into category folders and drop the retired head-review page

Group the top-level docs into docs/project, docs/design, docs/assets and
docs/process, each with its own README index. Delete the superseded
docs/screens/head-review page and sheets. Rewrite every markdown link,
absolute docs path and tool/test reference to the new locations, fix the
pre-existing broken anchors and remove the dead Joke Shop photo-board link.
check_docs OK, Python tooling 167/167.

.agents/skills/gig-line-blender-asset-contract/SKILL.md

@@ -24,7 +24,7 @@ The project contract and measured gates override any generic Blender advice.
 Blender MCP is optional interactive tooling; the headless flatpak CLI remains
 authoritative and CI never needs Blender or MCP. The `blender-skills` pack is
 optional, local guidance only, and gitignored. Setup and safety are in
-`docs/asset-tooling.md#optional-interactive-blender-mcp`.
+`docs/assets/asset-tooling.md#optional-interactive-blender-mcp`.
 
 ## Read first
 
@@ -33,11 +33,11 @@ skill alone:
 
 1. `AGENTS.md` — required workflow and verification.
 2. `TODO.md` and `MEMORY.md` — current track, claimed tasks, known gotchas.
-3. `docs/blender-assets.md` — library contract and command reference.
-4. `docs/asset-tooling.md` — exact rebuild/bake/capture commands.
-5. `docs/npc-model-sourcing.md` and `docs/3d-model-review.md` — accepted limits,
+3. `docs/assets/blender-assets.md` — library contract and command reference.
+4. `docs/assets/asset-tooling.md` — exact rebuild/bake/capture commands.
+5. `docs/assets/npc-model-sourcing.md` and `docs/assets/3d-model-review.md` — accepted limits,
    scorecards and known blockers.
-6. `docs/known-limitations.md` — limits that must not be silently “fixed” into
+6. `docs/design/known-limitations.md` — limits that must not be silently “fixed” into
    contract changes.
 
 The contract lives in code and docs, not in this skill. If they disagree, stop
@@ -114,7 +114,7 @@ only the specialists the task needs:
 - budget/LOD/collision: `asset-optimization`, `lod-pipeline`, `collision-proxy`
 - final review: `qa-review`
 
-If MCP is available, use it for interactive part exploration only; mirror the result into a scripted change or local `.blend`, then re-export and run the CLI audit/fit gates. Never make the build, CI, tests or runtime depend on MCP. Setup: `docs/asset-tooling.md#optional-interactive-blender-mcp`.
+If MCP is available, use it for interactive part exploration only; mirror the result into a scripted change or local `.blend`, then re-export and run the CLI audit/fit gates. Never make the build, CI, tests or runtime depend on MCP. Setup: `docs/assets/asset-tooling.md#optional-interactive-blender-mcp`.
 
 ### 4. Build or bake
 
@@ -185,7 +185,7 @@ gates run, and any accepted limit.
 - **Empty or stale captures** — close modals/pause, check the capture script's
   settle frames, and remove stale output directories before re-running.
 - **Pose harness mismatch** — the current `capture_npc_pose.gd` is blocked per
-  `docs/3d-model-review.md`; do not use its frames as pose evidence until the
+  `docs/assets/3d-model-review.md`; do not use its frames as pose evidence until the
   recipe is fixed.
 - **Asset test fails after import** — re-run audit/fit first, then import; if the
   manifest or AO path changed, rebuild the affected asset rather than editing
@@ -197,7 +197,7 @@ gates run, and any accepted limit.
 
 - [`references/asset-contract.md`](references/asset-contract.md) — full contract,
   inventory, file locations and provenance rules.
-- `docs/asset-tooling.md#optional-interactive-blender-mcp` — optional MCP installation, connection, safety and
+- `docs/assets/asset-tooling.md#optional-interactive-blender-mcp` — optional MCP installation, connection, safety and
   part-workflow instructions.
 - [`references/verification.md`](references/verification.md) — command matrix,
   capture gates, expected results and acceptance criteria.

.agents/skills/gig-line-blender-asset-contract/references/asset-contract.md

@@ -1,7 +1,7 @@
 # Asset Contract Reference
 
 This is a working summary. The authoritative sources remain
-`docs/blender-assets.md`, `docs/asset-tooling.md`, ADR-0013, the tests in
+`docs/assets/blender-assets.md`, `docs/assets/asset-tooling.md`, ADR-0013, the tests in
 `src/test/tests/` and the constants in `tools/blender_assets.py` /
 `tools/npc_pipeline.py`.
 

.agents/skills/gig-line-blender-asset-contract/references/verification.md

@@ -113,8 +113,8 @@ For each changed variant, inspect at least:
 - Day and night/LATE final-context frames.
 - Front, three-quarter and profile for a shape change.
 
-Accepted stylized limits are in `docs/3d-model-review.md` and
-`docs/known-limitations.md`. Do not turn an accepted limit into an unreviewed
+Accepted stylized limits are in `docs/assets/3d-model-review.md` and
+`docs/design/known-limitations.md`. Do not turn an accepted limit into an unreviewed
 contract change.
 
 ## Final diff review