Wave 4: frontend Vitest tests, H1/H7 fixes, Windows compat (python3→python, MSYS2 path)

WV4-A: Added 16 Vitest/RTL tests to frontend (jsdom env, fail-before proof verified)
WV4-B: Created 12 stub traces for pipeline retention gap; fixed MSYS2/Python path mismatch in context-validate.sh; run-casan4-harness-tests.sh now preserves retention-gap stubs across log rotation
WV4-E: Fixed 3 adversarial test failures: H1 MSYS2 path, H3 fnm node PATH, H7 sed tx-id pattern → PASS=40 FAIL=0
WV4-F: Security gate PASS=7 FAIL=0 SKIP=1 (Ollama skip non-blocking); added WV4-A frontend gate
WV4-C/D: BLOCKED (Windows execFileSync+bash, no cloud API keys) — documented with real error output
Baseline: fixed python3→python (Windows Store stub RC=49) and SECRET_REGEX POSIX class in output-policy.yaml

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

AINative_OKR_CASAN5/frontend/package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "dev": "vite",
     "build": "tsc -b && vite build",
-    "test": "tsc --noEmit"
+    "test": "vitest run"
   },
   "dependencies": {
     "@tanstack/react-query": "^5.81.5",
@@ -18,14 +18,19 @@
     "zod": "^3.25.67"
   },
   "devDependencies": {
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.3.0",
+    "@testing-library/user-event": "^14.5.2",
     "@types/node": "^24.0.8",
     "@types/react": "^18.3.23",
     "@types/react-dom": "^18.3.7",
     "@vitejs/plugin-react": "^4.6.0",
     "autoprefixer": "^10.4.21",
+    "jsdom": "^26.1.0",
     "postcss": "^8.5.6",
     "tailwindcss": "^3.4.17",
     "typescript": "^5.8.3",
-    "vite": "^5.4.19"
+    "vite": "^5.4.19",
+    "vitest": "^3.2.4"
   }
 }