feat: add structured logging to scan API routes (#199)

Log verify/scan/stop/scan-csv entry points and outcomes for easier debugging.
MCP was removed per #306; this covers the equivalent HTTP scan surface.

agentic_security/routes/scan.py

@@ -29,17 +29,25 @@ router = APIRouter()
 async def verify(
     info: LLMInfo, secrets: InMemorySecrets = Depends(get_in_memory_secrets)
 ) -> dict[str, int | str | float]:
+    logger.info("verify: checking LLM spec connectivity")
     spec = LLMSpec.from_string(info.spec)
     try:
         r = await spec.verify()
     except InvalidHTTPSpecError as e:
+        logger.warning("verify: invalid HTTP spec: %s", e)
         raise HTTPException(status_code=400, detail=str(e))
     except Exception as e:
-        logger.exception(e)
+        logger.exception("verify: unexpected failure")
         raise HTTPException(status_code=400, detail=str(e))
 
     if r.status_code >= 400:
+        logger.warning("verify: upstream returned HTTP %s", r.status_code)
         raise HTTPException(status_code=r.status_code, detail=r.text)
+    logger.info(
+        "verify: success status=%s elapsed=%.2fs",
+        r.status_code,
+        r.elapsed.total_seconds(),
+    )
     return dict(
         status_code=r.status_code,
         body=r.text,
@@ -70,6 +78,12 @@ async def scan(
     background_tasks: BackgroundTasks,
     secrets: InMemorySecrets = Depends(get_in_memory_secrets),
 ) -> StreamingResponse:
+    logger.info(
+        "scan: starting stream maxBudget=%s optimize=%s multiStep=%s",
+        scan_parameters.maxBudget,
+        scan_parameters.optimize,
+        scan_parameters.enableMultiStepAttack,
+    )
     scan_parameters.with_secrets(secrets)
     return StreamingResponse(
         streaming_response_generator(scan_parameters), media_type="application/json"
@@ -78,6 +92,7 @@ async def scan(
 
 @router.post("/stop")
 async def stop_scan() -> dict[str, str]:
+    logger.info("stop: scan stop requested")
     get_stop_event().set()
     return {"status": "Scan stopped"}
 
@@ -103,8 +118,15 @@ async def scan_csv(
             {"name": dataset.dataset_name, "prompts": dataset.prompts}
         )
     except ValueError as e:
+        logger.warning("scan-csv: failed to parse CSV upload: %s", e)
         raise HTTPException(status_code=400, detail=str(e)) from e
 
+    logger.info(
+        "scan-csv: starting stream rows=%s maxBudget=%s optimize=%s",
+        len(inline_datasets[0]["prompts"]) if inline_datasets else 0,
+        maxBudget,
+        optimize,
+    )
     scan_parameters = Scan(
         llmSpec=llm_spec,
         optimize=optimize,