feat(deploy): HuggingFace Static Space for frontend (#34)

## Changes
- Add frontend/.env.production with backend API URL
- Update frontend/README.md with HF Spaces YAML metadata
- Add path-based CI filtering (dorny/paths-filter)
- Fix frontend-build conditional to handle skipped jobs
- Update spec 36 to document Vite 7 tsconfig pattern

## CI Optimization
- Backend jobs only run on src/, tests/, pyproject.toml changes
- Frontend jobs only run on frontend/** changes
- Push to main runs full CI (safety gate)

Co-authored-by: CodeRabbit <coderabbit@users.noreply.github.com>

.github/workflows/ci.yml

@@ -7,6 +7,11 @@ on:
     branches: [main]
   workflow_dispatch:
     inputs:
+      run_all:
+        description: 'Run all jobs regardless of path filters'
+        required: false
+        default: false
+        type: boolean
       run_integration:
         description: 'Run integration tests (requires HuggingFace download)'
         required: false
@@ -14,7 +19,35 @@ on:
         type: boolean
 
 jobs:
+  # Detect which paths changed to conditionally run jobs
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      backend: ${{ steps.filter.outputs.backend }}
+      frontend: ${{ steps.filter.outputs.frontend }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            backend:
+              - 'src/**'
+              - 'tests/**'
+              - 'pyproject.toml'
+              - 'requirements.txt'
+              - 'Dockerfile'
+              - '.github/workflows/ci.yml'
+            frontend:
+              - 'frontend/**'
+              - '.github/workflows/ci.yml'
+
+  # Backend Jobs - run on backend changes, main push, or manual override
+  # Design: Push to main always runs full CI (safety gate), PRs use path filtering (efficiency)
   lint:
+    needs: changes
+    if: needs.changes.outputs.backend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -35,6 +68,8 @@ jobs:
         run: uv run ruff format --check .
 
   typecheck:
+    needs: changes
+    if: needs.changes.outputs.backend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -52,6 +87,8 @@ jobs:
         run: uv run mypy src/
 
   test:
+    needs: changes
+    if: needs.changes.outputs.backend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -107,8 +144,10 @@ jobs:
         env:
           HF_HOME: /tmp/hf_cache
 
-  # Frontend Jobs
+  # Frontend Jobs - run on frontend changes, main push, or manual override
   frontend-lint:
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -126,6 +165,8 @@ jobs:
       - run: npm run lint
 
   frontend-typecheck:
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -143,6 +184,8 @@ jobs:
       - run: npx tsc --noEmit
 
   frontend-test:
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -167,6 +210,8 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
 
   frontend-e2e:
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -193,8 +238,16 @@ jobs:
           retention-days: 7
 
   frontend-build:
+    needs: [changes, frontend-lint, frontend-typecheck, frontend-test]
+    # Build if: (1) frontend changed OR push to main OR manual run_all, AND (2) no prerequisite failures
+    # Note: Uses != 'failure' instead of == 'success' to handle skipped jobs gracefully
+    if: |
+      always() &&
+      (needs.changes.outputs.frontend == 'true' || github.event_name == 'push' || (github.event_name == 'workflow_dispatch' && inputs.run_all)) &&
+      needs.frontend-lint.result != 'failure' &&
+      needs.frontend-typecheck.result != 'failure' &&
+      needs.frontend-test.result != 'failure'
     runs-on: ubuntu-latest
-    needs: [frontend-lint, frontend-typecheck, frontend-test]
     defaults:
       run:
         working-directory: frontend

docs/specs/frontend/36-frontend-without-gradio-hf-spaces.md

@@ -207,28 +207,48 @@ export default defineConfig({
 })
 ```
 
-### tsconfig.json
+### TypeScript Configuration (Vite 7 Project References Pattern)
 
+Vite 7 uses a project references pattern for better separation of app, test, and build configs:
+
+**tsconfig.json** (root - references only):
+```json
+{
+  "files": [],
+  "references": [
+    { "path": "./tsconfig.app.json" },
+    { "path": "./tsconfig.node.json" },
+    { "path": "./tsconfig.test.json" }
+  ]
+}
+```
+
+**tsconfig.app.json** (application code):
 ```json
 {
   "compilerOptions": {
-    "target": "ES2020",
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+    "target": "ES2022",
     "useDefineForClassFields": true,
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "module": "ESNext",
+    "types": ["vite/client"],
     "skipLibCheck": true,
     "moduleResolution": "bundler",
     "allowImportingTsExtensions": true,
-    "isolatedModules": true,
+    "verbatimModuleSyntax": true,
     "moduleDetection": "force",
     "noEmit": true,
     "jsx": "react-jsx",
     "strict": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
-    "noFallthroughCasesInSwitch": true
+    "erasableSyntaxOnly": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedSideEffectImports": true
   },
-  "include": ["src"]
+  "include": ["src"],
+  "exclude": ["src/test", "src/mocks", "src/**/*.test.tsx", "src/**/*.test.ts"]
 }
 ```
 
@@ -710,7 +730,7 @@ colorTo: purple
 sdk: static
 app_file: dist/index.html
 app_build_command: npm run build
-# CRITICAL: Vite 6 requires Node.js >= 20. HF Spaces defaults to Node 18.
+# CRITICAL: Vite 7 requires Node.js >= 20. HF Spaces defaults to Node 18.
 # Without this, the build will fail or produce warnings.
 nodejs_version: "20"
 pinned: false

frontend/.env.production

@@ -0,0 +1,3 @@
+# Production environment - HuggingFace Spaces deployment
+# Backend API running on Docker Space with T4 GPU
+VITE_API_URL=https://vibecodermcswaggins-stroke-deepisles-demo.hf.space

frontend/README.md

@@ -6,8 +6,7 @@ colorTo: purple
 sdk: static
 app_file: dist/index.html
 app_build_command: npm run build
-# CRITICAL: Vite 6 requires Node.js >= 20. HF Spaces defaults to Node 18.
-# Without this, the build will fail or produce warnings.
+# CRITICAL: Vite 7 requires Node.js >= 20. HF Spaces defaults to Node 18.
 nodejs_version: "20"
 pinned: false
 ---
@@ -61,5 +60,20 @@ npm run build        # Production build
 Set `VITE_API_URL` to point to your backend:
 
 ```bash
+# Local development (default)
 VITE_API_URL=http://localhost:7860 npm run dev
+
+# Production is configured in .env.production
+# Points to: https://vibecodermcswaggins-stroke-deepisles-demo.hf.space
+```
+
+## Deployment
+
+This frontend deploys as a **HuggingFace Static Space**. The backend API runs on a separate Docker Space with GPU.
+
+```bash
+# Build for production (uses .env.production)
+npm run build
+
+# The dist/ folder is deployed to HF Static Space
 ```