feat(client): hair highlight swatch + manifest JSON for exports (#719, #720)

#719: Add display-only hair highlight swatch (Option B) — auto-derived
from primary tint, non-interactive (MOUSE_FILTER_IGNORE).

#720: Remove DirAccess.open() fallback scanning (breaks in PCK exports).
Fully populate manifest.json (11 body types, 14 hair, 4 heads, 4
eyebrows, 8 clothing). Add tooling/generate-character-manifest script
and make manifest target for regeneration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Makefile

@@ -11,7 +11,8 @@ GODOT := $(shell command -v godot4 2>/dev/null || command -v godot 2>/dev/null)
        build-sr-voice run-sr-voice test-voice-mock test-voice-real \
        perf-baseline debug-schedule \
        test-ipc-fixtures test-ipc-protocol test-ipc-integration test-ipc-benchmark \
-       screenshot visual-movie test-visual visual-update
+       screenshot visual-movie test-visual visual-update \
+       manifest
 
 # --- Configuration ---
 
@@ -62,6 +63,7 @@ help:
 	@echo "  make test-visual        Run visual golden regression tests"
 	@echo "  make visual-update      Regenerate visual goldens and stage for commit"
 	@echo ""
+	@echo "  make manifest           Regenerate assets/characters/manifest.json from asset dirs (#720)"
 	@echo "  make pre-pr             Run all pre-PR checks (lint, build, test, validate, fixtures)"
 	@echo "  make pre-pr-server      Server-scoped pre-PR (lint, build, test, fixtures)"
 	@echo "  make pre-pr-client      Client-scoped pre-PR (lint, build, test)"
@@ -399,6 +401,12 @@ test-voice-real:
 	cd server && cargo test --test voice_pipeline -- --nocapture
 	@echo "Results: .tmp/voice-test/results.txt"
 
+# --- Asset manifest ---
+
+manifest:
+	@tooling/generate-character-manifest
+	@echo "Manifest regenerated — commit client/assets/characters/manifest.json if changed."
+
 # --- Clean ---
 
 clean: