feat: add AI Digital Employee agent orchestrator with pipeline tracking

- New AgentPipeline model with JSONB pipeline_data for stages/leads/summary
- AgentOrchestrator service chains DiscoveryService search→analyze→outreach→auto-save
- 3 new API endpoints: POST /agent/start, GET /agent/pipelines, GET /agent/{id}
- Full Agent dashboard Vue component with stats, pipeline grid, leads table, outreach preview
- Sidebar redesigned with AI Agent as primary entry point
- Updated PROGRESS.md, AGENTS.md, DATABASE_SCHEMA.md with latest state

backend/app/api/v1/agent.py

@@ -0,0 +1,56 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.ext.asyncio import AsyncSession
+from pydantic import BaseModel
+
+from app.database import get_db
+from app.api.v1.deps import get_current_user_id
+from app.services.agent_orchestrator import AgentOrchestrator
+
+router = APIRouter()
+
+
+class StartPipelineRequest(BaseModel):
+    product_name: str
+    product_description: str = ""
+    target_market: str
+
+
+@router.post("/start")
+async def start_pipeline(
+    req: StartPipelineRequest,
+    user_id: str = Depends(get_current_user_id),
+    db: AsyncSession = Depends(get_db),
+):
+    orchestrator = AgentOrchestrator(db)
+    result = await orchestrator.start_pipeline(
+        user_id=user_id,
+        product_name=req.product_name,
+        product_description=req.product_description,
+        target_market=req.target_market,
+    )
+    return {"code": 0, "data": result}
+
+
+@router.get("/pipelines")
+async def list_pipelines(
+    page: int = Query(1, ge=1),
+    size: int = Query(20, ge=1, le=100),
+    user_id: str = Depends(get_current_user_id),
+    db: AsyncSession = Depends(get_db),
+):
+    orchestrator = AgentOrchestrator(db)
+    result = await orchestrator.list_pipelines(user_id, page=page, size=size)
+    return {"code": 0, "data": result}
+
+
+@router.get("/{pipeline_id}")
+async def get_pipeline(
+    pipeline_id: str,
+    user_id: str = Depends(get_current_user_id),
+    db: AsyncSession = Depends(get_db),
+):
+    orchestrator = AgentOrchestrator(db)
+    result = await orchestrator.get_pipeline(pipeline_id, user_id)
+    if not result:
+        raise HTTPException(status_code=404, detail="Pipeline not found")
+    return {"code": 0, "data": result}