PR_26177_CHARLIE_018-sprites-testable-mvp-completion

[ToolboxAid]

Summary

• Completes the Sprites MVP so creators can manually test the tool from Toolbox.
• Removes placeholder-era visible wording and replaces the static wireframe with a Theme V2 table-first Sprites workspace.
• Adds an API-backed Sprites contract over the existing asset repository for list/create/edit/archive.
• Keeps Palette/Colors as the reusable color SSoT by storing only paletteColorKey references.
• Adds explicit preview/reference unavailable states and destructive delete protection.

Validation

• PASS node ./scripts/run-node-test-files.mjs tests/dev-runtime/SpritesAssetRepository.test.mjs
• PASS npx playwright test tests/playwright/tools/SpritesToolMvp.spec.mjs --workers=1 --reporter=list
• PASS npx playwright test tests/playwright/tools/ToolboxRoutePages.spec.mjs --workers=1 --reporter=list (11 passed)
• PASS file/content check: toolbox/sprites/index.html no longer contains Not implemented yet., Setup, Plan sprite creation, future rebuild work, Inspector, or Output.
• PASS file/content check: Sprites controls are wired in assets/toolbox/sprites/js/index.js.
• PASS metadata check: Sprites route is toolbox/sprites/index.html and release channel is wireframe.
• PASS git diff --check

Artifact

• tmp/PR_26177_CHARLIE_018-sprites-testable-mvp-completion_delta.zip

Do not merge until Owner approval.