[KM-652] feat(analysis): GET /analysis/{id} + GET /analysis (read endpoints)

The FE workspace + sidebar need to read analysis state back; only create
existed. Add:
- GET /analysis/{id} — full state (8 fields) + bound data_source_ids; 404 if absent
- GET /analysis?user_id= — a user's analyses, most-recently-updated first (summary)

Extract _serialize_state so create + detail share one payload shape.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/api/v1/analysis.py

@@ -13,6 +13,7 @@ import uuid
 
 from fastapi import APIRouter, Depends, HTTPException
 from pydantic import BaseModel, Field
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.db.postgres.connection import get_db
@@ -24,6 +25,30 @@ logger = get_logger("analysis_api")
 router = APIRouter(prefix="/api/v1", tags=["Analysis"])
 
 
+def _serialize_state(row: AnalysisStateRow, data_source_ids: list[str]) -> dict:
+    """The full analysis payload: the 8 state fields + the bound source ids."""
+    return {
+        "id": row.id,
+        "analysis_title": row.analysis_title,
+        "problem_statement": row.problem_statement,
+        "problem_validated": row.problem_validated,
+        "owner_id": row.owner_id,
+        "report_id": row.report_id,
+        "data_source_ids": data_source_ids,
+        "created_at": row.created_at.isoformat() if row.created_at else None,
+        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
+    }
+
+
+async def _bound_source_ids(db: AsyncSession, analysis_id: str) -> list[str]:
+    result = await db.execute(
+        select(AnalysisDataSourceRow.source_id).where(
+            AnalysisDataSourceRow.analysis_id == analysis_id
+        )
+    )
+    return list(result.scalars().all())
+
+
 class CreateAnalysisRequest(BaseModel):
     user_id: str
     analysis_title: str = "New analysis"
@@ -80,15 +105,45 @@ async def create_analysis(
     return {
         "status": "success",
         "message": "Analysis created successfully",
-        "data": {
-            "id": state_row.id,
-            "analysis_title": state_row.analysis_title,
-            "problem_statement": state_row.problem_statement,
-            "problem_validated": state_row.problem_validated,
-            "owner_id": state_row.owner_id,
-            "report_id": state_row.report_id,
-            "data_source_ids": bound_ids,
-            "created_at": state_row.created_at.isoformat() if state_row.created_at else None,
-            "updated_at": state_row.updated_at.isoformat() if state_row.updated_at else None,
-        },
+        "data": _serialize_state(state_row, bound_ids),
+    }
+
+
+@router.get("/analysis")
+@log_execution(logger)
+async def list_analyses(user_id: str, db: AsyncSession = Depends(get_db)):
+    """List a user's analyses, most-recently-updated first (Analysis sidebar).
+
+    Summary fields only (no per-row source bindings — fetch those via the detail
+    endpoint) to keep the list a single query.
+    """
+    result = await db.execute(
+        select(AnalysisStateRow)
+        .where(AnalysisStateRow.owner_id == user_id)
+        .order_by(AnalysisStateRow.updated_at.desc())
+    )
+    rows = result.scalars().all()
+    return {
+        "status": "success",
+        "data": [
+            {
+                "id": r.id,
+                "analysis_title": r.analysis_title,
+                "problem_validated": r.problem_validated,
+                "report_id": r.report_id,
+                "updated_at": r.updated_at.isoformat() if r.updated_at else None,
+            }
+            for r in rows
+        ],
     }
+
+
+@router.get("/analysis/{analysis_id}")
+@log_execution(logger)
+async def get_analysis(analysis_id: str, db: AsyncSession = Depends(get_db)):
+    """Read one analysis's state + bound data sources (the FE workspace render)."""
+    row = await db.get(AnalysisStateRow, analysis_id)
+    if row is None:
+        raise HTTPException(status_code=404, detail=f"Analysis {analysis_id!r} not found.")
+    data_source_ids = await _bound_source_ids(db, analysis_id)
+    return {"status": "success", "data": _serialize_state(row, data_source_ids)}