Release v0.4.0: UX pipeline, game-dev improvements

## New Skills (9)
- /quick-design: lightweight spec path for small changes (bypasses full GDD pipeline)
- /story-readiness: validates stories are implementation-ready before pickup
- /story-done: end-of-story completion review (criteria verification, deviation check, status update)
- /sprint-status: fast 30-line sprint snapshot, read-only
- /ux-design: guided section-by-section UX spec authoring (screen/flow/HUD/patterns)
- /ux-review: UX spec validation with APPROVED/NEEDS REVISION/MAJOR REVISION verdict
- /architecture-review, /create-architecture, /create-control-manifest,
  /create-epics-stories, /propagate-design-change, /review-all-gdds (pipeline completion)

## New Templates (7)
- player-journey.md: 6-phase emotional arc, critical moments, retention hooks
- difficulty-curve.md: difficulty axes, onboarding ramp, cross-system interactions
- ux-spec.md: per-screen UX spec with states, interaction map, data requirements, events
- hud-design.md: whole-game HUD with philosophy, info architecture, element specs
- accessibility-requirements.md: project-wide accessibility tier commitment and audit
- interaction-pattern-library.md: 26 standard + game-specific patterns with full state specs
- architecture-traceability.md: GDD requirements to ADR coverage matrix

## Updated Skills & Templates
- gate-check: Vertical Slice hard gate, playtesting strengthened, UX artifacts required
- team-ui: full UX pipeline integration (/ux-design + /ux-review + accessibility-specialist)
- game-design-document: Game Feel section (input latency, animation frames, impact moments)
- implementation-agent-protocol: /story-done as explicit final step of every story
- architecture-decision, design-system: pipeline completion updates

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

.claude/docs/templates/technical-design-document.md

@@ -8,6 +8,20 @@
 - **Related ADR**: [ADR-XXXX if applicable]
 - **Related Design Doc**: [Link to game design doc this implements]
 
+## Engine API Surface
+
+| Field | Value |
+|-------|-------|
+| **Engine** | [e.g. Godot 4.6 / Unity 6 / Unreal Engine 5.4] |
+| **APIs Depended On** | [Specific classes/methods/nodes used, version-pinned — e.g. `CharacterBody3D.move_and_slide() (Godot 4.x)`] |
+| **References Consulted** | [engine-reference docs read before writing this — e.g. `docs/engine-reference/godot/modules/physics.md`] |
+| **Post-Cutoff Features Used** | [Features from engine versions beyond LLM training cutoff, or "None"] |
+| **Unverified Assumptions** | [API behaviours assumed but not yet tested against the target version, or "None"] |
+| **Engine Upgrade Risk** | [LOW / MEDIUM / HIGH — how fragile is this design if the engine version changes?] |
+
+> **Rule**: If any **Unverified Assumptions** are listed, this document cannot be marked
+> as Accepted until those assumptions are validated in the actual engine environment.
+
 ## Overview
 [2-3 sentence summary of what this system does and why it exists]