Add design-first workflow aligned with opencode boilerplate

- New commands: /define-design, /update-design, /generate-app (web | flutter | winui3)
- New skills: ui-design, design-tokens, platform-ui-generation
- /add-feature: check design spec before implementation (Step 3.5) and reconcile all six persistent docs after implementation (Step 8)
- /setup-project: automatic document creation with self-check checkpoints
- CLAUDE.md: document docs/design/, .claude/ configuration, and the design phase in the development process
- Enrich subagent descriptions; allowlist new skills in settings.json
- Add docs/design/README.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.claude/commands/update-design.md

@@ -0,0 +1,89 @@
+---
+description: Refine the design before /generate-app, or update it when a feature changes the UI (blueprint first, then tokens, brief, and SVGs)
+---
+
+# Update Design
+
+This command updates the design specification. It is used in two situations: (1) to refine the UI/UX **before** running `/generate-app` (e.g. adjusting screens, tokens, or layout after reviewing the initial design), and (2) to update the design when a feature changes the UI. It updates the structured design files **only** — it does **not** implement application code unless explicitly requested.
+
+**Change description**: `$ARGUMENTS` (e.g. `/update-design add a profile screen with avatar and edit form`)
+
+## How to Run
+
+```bash
+claude
+> /update-design add a profile screen with avatar and edit form
+```
+
+## Pre-Run Check
+
+Confirm the design files exist. If they are missing, stop and tell the user to run `/define-design` first:
+
+- `docs/design/design-brief.md`
+- `docs/design/design-tokens.json`
+- `docs/design/ui-blueprint.json`
+- `docs/design/platform-mapping.md`
+
+## Procedure
+
+### Step 0: Read the Inputs
+
+Read:
+
+- The existing design files listed above
+- `docs/product-requirements.md` and `docs/functional-design.md` for context
+- The change description provided in `$ARGUMENTS`
+
+### Step 1: Update `ui-blueprint.json` First
+
+The blueprint is the source of truth, so it is always updated first. Add/modify screens, components, variants, states, routes, and actions to reflect the requested change. Keep the JSON valid and consistent with the existing schema.
+
+### Step 2: Update `design-tokens.json` (if needed)
+
+If the change introduces new colors, spacing, typography, radius, shadows, or animations, add the corresponding tokens here. Reuse existing tokens where possible; do not duplicate. Use semantic names. No hard-coded values should be needed downstream.
+
+### Step 3: Update `design-brief.md` (if the direction changes)
+
+If the change affects the overall design direction (visual mood, layout principles, navigation principles, accessibility), update the brief. If it is a localized screen/component change, leave the brief unchanged.
+
+### Step 4: Update `platform-mapping.md` (if needed)
+
+If the change introduces a new platform target or a new kind of mapping (e.g. a new component family that maps differently per platform), update the mapping. Otherwise leave it unchanged.
+
+### Step 5: Regenerate Affected SVG Wireframes
+
+For every screen added or modified in `ui-blueprint.json`, generate or regenerate the corresponding SVG under `docs/design/screens/`. Remember: SVGs are visual references only — the blueprint is the source of truth.
+
+### Step 6: Consistency Check
+
+- Every screen in `ui-blueprint.json` has a matching SVG.
+- Token names referenced in the blueprint exist in `design-tokens.json`.
+- The brief and mapping remain consistent with the blueprint.
+
+### Step 7: Do Not Implement Code
+
+Do **not** modify application code in this command. If the user also wants the code updated, they should run `/add-feature` (which reads the updated design files) or ask explicitly.
+
+## Completion Criteria
+
+- `ui-blueprint.json` has been updated (source of truth).
+- `design-tokens.json` updated only if new tokens were needed.
+- `design-brief.md` updated only if the direction changed.
+- `platform-mapping.md` updated only if mappings changed.
+- Affected SVG wireframes regenerated.
+- No application code was changed.
+
+Completion message:
+```
+"Design has been updated.
+
+Updated:
+✅ docs/design/ui-blueprint.json   (source of truth)
+✅ docs/design/design-tokens.json   (if new tokens were needed)
+✅ docs/design/design-brief.md      (if the direction changed)
+✅ docs/design/platform-mapping.md  (if mappings changed)
+✅ docs/design/screens/*.svg        (regenerated as needed)
+
+Note: application code was not changed. Run /add-feature to implement the change, respecting the updated design.
+"
+```