Add task detail view, pipeline visualization, approve/reject workflow

API (web/api.py) — 5 new endpoints:
  GET  /api/tasks/{id}/pipeline — agent_logs as pipeline steps
  GET  /api/tasks/{id}/full — task + steps + related decisions
  POST /api/tasks/{id}/approve — mark done, optionally add decision
  POST /api/tasks/{id}/reject — return to pending with reason
  POST /api/tasks/{id}/run — launch pipeline in background (202)

Frontend:
  TaskDetail (/task/:id) — full task page with:
    - Pipeline graph: role cards with icons, arrows, status colors
    - Click step → expand output (pre-formatted, JSON detected)
    - Action bar: Approve (with optional decision), Reject, Run Pipeline
    - Polling for live pipeline updates
  Dashboard: review_tasks badge ("awaiting review" in yellow)
  ProjectView: task rows are now clickable links to /task/:id

Runner: output_summary no longer truncated (full output for GUI).
Models: get_project_summary includes review_tasks count.

13 new API tests, 105 total, all passing. Frontend builds clean.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agents/runner.py

@@ -78,7 +78,7 @@ def run_agent(
         agent_role=role,
         action="execute",
         input_summary=f"task={task_id}, model={model}",
-        output_summary=output_text[:500] if output_text else None,
+        output_summary=output_text or None,
         tokens_used=result.get("tokens_used"),
         model=model,
         cost_usd=result.get("cost_usd"),