feat(ralph): smart gates + DAG + dashboard live (W3)

Restructurare Ralph QC loop pe smart gate dispatcher tag-driven (în loc de
5 faze fixe), DAG dependsOn cu propagare blocked, retry guard 3-strike, rate
limit detection, plus dashboard live cu polling 5s.

Changes:
- tools/ralph_prd_generator.py: parametru optional final_plan_path; când e
  furnizat, invocă Claude Opus pe final-plan.md pentru extragere user stories
  cu schema extinsă (tags, dependsOn, acceptanceCriteria 3-5). Backward compat
  păstrat — fără final_plan_path, fallback la heuristic-ul vechi.
- tools/ralph/prd-template.json: schema W3 (tags[], dependsOn[], retries,
  failed, blocked, failureReason, requiresDesignReview).
- tools/ralph/prompt.md: 4 faze (impl, base quality, smart gates, commit) +
  dispatcher pe story.tags. Tags vide → run-all-gates fallback (safe default).
- tools/ralph_dag.py (nou): tag validation heuristic anti-silent-regression
  (force ui dacă diff atinge .vue/.tsx/.html/.css/.scss; force db pentru
  migrations sau .sql; force vercel dacă există vercel.json) + topological
  sort cu blocked propagation + atomic prd.json updates.
- tools/ralph/ralph.sh: --max-turns 30, DAG-aware story selection, retry
  counter cu auto-fail la 3, rate limit detection (sleep 30min + 1 retry),
  CLI subcommands prin tools/ralph_dag.py helper.
- dashboard/handlers/ralph.py (nou): /api/ralph/status + /<slug>/log + /prd
  + /stop. Defensive vs corrupt prd.json. Sandbox-ed PID kill.
- dashboard/ralph.html (nou): live cards 3/2/1 col responsive, polling 5s,
  drawer pentru log/PRD viewer, status colors (--status-running/blocked/
  failed/complete declarate inline), Lucide icons cu aria-labels.
- dashboard/api.py: mount /api/ralph/* (GET status/log/prd, POST stop).
- tests/: 72 teste noi (smart gates, DAG, retry, dashboard endpoint).

Note arhitecturale:
- Polling 5s ales peste SSE/WebSocket (suficient pentru iter Ralph 8-15min)
- Tag validation rulează POST-iter pe diff git pentru anti-silent-regression
- Rate limit retry: 1 dată per rulare, apoi mark failed=rate_limited

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/ralph/prd-template.json

@@ -2,6 +2,17 @@
   "projectName": "feature-name",
   "branchName": "ralph/feature-name",
   "description": "Descriere scurtă a feature-ului",
+  "techStack": {
+    "type": "python",
+    "commands": {
+      "start": "python main.py",
+      "build": "",
+      "lint": "ruff check .",
+      "typecheck": "mypy .",
+      "test": "pytest"
+    },
+    "port": 8000
+  },
   "userStories": [
     {
       "id": "US-001",
@@ -12,7 +23,15 @@
         "Criteriu specific și verificabil",
         "npm run typecheck passes"
       ],
+      "tags": [],
+      "dependsOn": [],
+      "requiresBrowserCheck": false,
+      "requiresDesignReview": false,
       "passes": false,
+      "failed": false,
+      "blocked": false,
+      "retries": 0,
+      "failureReason": "",
       "notes": ""
     }
   ]