feat: add fundamentals parity reporting

app/routers/admin.py

@@ -453,6 +453,36 @@ async def toggle_job(
     )
 
 
+@router.get("/admin/fundamentals-parity", response_model=APIEnvelope)
+async def get_fundamentals_parity_report(
+    _admin: User = Depends(require_admin),
+):
+    """Latest read-only A5 source/score comparison, or null before first run."""
+    return APIEnvelope(
+        status="success", data=admin_service.get_fundamentals_parity_report()
+    )
+
+
+@router.get("/admin/fundamentals-parity/csv", response_model=APIEnvelope)
+async def get_fundamentals_parity_csv(
+    _admin: User = Depends(require_admin),
+):
+    """Latest flattened A5 report for an authenticated browser download."""
+    artifact = admin_service.get_fundamentals_parity_csv()
+    data = None if artifact is None else {"filename": artifact[0], "content": artifact[1]}
+    return APIEnvelope(status="success", data=data)
+
+
+@router.get("/admin/fundamentals-parity/json", response_model=APIEnvelope)
+async def get_fundamentals_parity_json(
+    _admin: User = Depends(require_admin),
+):
+    """Canonical A5 JSON artifact for an authenticated browser download."""
+    artifact = admin_service.get_fundamentals_parity_json()
+    data = None if artifact is None else {"filename": artifact[0], "content": artifact[1]}
+    return APIEnvelope(status="success", data=data)
+
+
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 # System events (operational warnings / errors)
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