fix(logging): replace structlog with stdlib logging to prevent broken pipe crashes

structlog fails with BrokenPipeError when stdout is redirected (e.g., background
processes, Docker logs). Replace all structlog.get_logger() calls with
logging.getLogger() and convert keyword-style log calls to %-format strings.

Also removes stale Docs/tasks.md (2028 lines) and updates Robot Framework
tests to match current API behavior.

src/server/middleware/error_handler.py

@@ -74,9 +74,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle authentication errors (401)."""
         logger.warning(
-            "Authentication error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Authentication error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -95,9 +94,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle authorization errors (403)."""
         logger.warning(
-            "Authorization error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Authorization error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -116,9 +114,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle validation errors (422)."""
         logger.info(
-            "Validation error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Validation error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -137,9 +134,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle bad request errors (400)."""
         logger.info(
-            "Bad request error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Bad request error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -158,9 +154,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle not found errors (404)."""
         logger.info(
-            "Not found error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Not found error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -179,9 +174,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle conflict errors (409)."""
         logger.info(
-            "Conflict error: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Conflict error: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -200,9 +194,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle rate limit errors (429)."""
         logger.warning(
-            "Rate limit exceeded: %s",
-            exc.message,
-            extra={"details": exc.details, "path": str(request.url.path)},
+            "Rate limit exceeded: %s details=%s path=%s",
+            exc.message, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -221,13 +214,8 @@ def register_exception_handlers(app: FastAPI) -> None:
     ) -> JSONResponse:
         """Handle generic API exceptions."""
         logger.error(
-            "API error: %s",
-            exc.message,
-            extra={
-                "error_code": exc.error_code,
-                "details": exc.details,
-                "path": str(request.url.path),
-            },
+            "API error: %s error_code=%s details=%s path=%s",
+            exc.message, exc.error_code, exc.details, str(request.url.path),
         )
         return JSONResponse(
             status_code=exc.status_code,
@@ -245,10 +233,9 @@ def register_exception_handlers(app: FastAPI) -> None:
         request: Request, exc: Exception
     ) -> JSONResponse:
         """Handle unexpected exceptions."""
-        logger.exception(
-            "Unexpected error: %s",
-            str(exc),
-            extra={"path": str(request.url.path)},
+        logger.error(
+            "Unexpected error: %s path=%s",
+            str(exc), str(request.url.path),
         )
 
         # Log full traceback for debugging