graph, tests: Fix clippy warning and update _logs introspection schema

Use map_while instead of filter_map on lines() iterator to properly
handle read errors, and add missing orderDirection argument to the
_logs field in mock introspection JSON.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fordN

graph/src/components/log_store/file.rs

@@ -123,7 +123,7 @@ impl FileLogStore {
 
         let kept_entries: Vec<String> = reader
             .lines()
-            .filter_map(|line| line.ok())
+            .map_while(Result::ok)
             .filter(|line| {
                 // Parse timestamp from log entry
                 if let Some(entry) = self.parse_line(line) {

store/test-store/tests/graphql/mock_introspection.json

@@ -825,6 +825,16 @@
                   "ofType": null
                 },
                 "defaultValue": "0"
+              },
+              {
+                "name": "orderDirection",
+                "description": "Sort direction for results. Default: desc (newest first).",
+                "type": {
+                  "kind": "ENUM",
+                  "name": "OrderDirection",
+                  "ofType": null
+                },
+                "defaultValue": "desc"
               }
             ],
             "type": {