fix(hook-message-injector): preserve agent info with two-pass message lookup

findNearestMessageWithFields now has a fallback pass that returns
messages with ANY useful field (agent OR model) instead of requiring
ALL fields. This prevents parentAgent from being lost when stored
messages don't have complete model info.

src/features/hook-message-injector/injector.ts

@@ -16,6 +16,7 @@ export function findNearestMessageWithFields(messageDir: string): StoredMessage
       .sort()
       .reverse()
 
+    // First pass: find message with ALL fields (ideal)
     for (const file of files) {
       try {
         const content = readFileSync(join(messageDir, file), "utf-8")
@@ -27,6 +28,20 @@ export function findNearestMessageWithFields(messageDir: string): StoredMessage
         continue
       }
     }
+
+    // Second pass: find message with ANY useful field (fallback)
+    // This ensures agent info isn't lost when model info is missing
+    for (const file of files) {
+      try {
+        const content = readFileSync(join(messageDir, file), "utf-8")
+        const msg = JSON.parse(content) as StoredMessage
+        if (msg.agent || (msg.model?.providerID && msg.model?.modelID)) {
+          return msg
+        }
+      } catch {
+        continue
+      }
+    }
   } catch {
     return null
   }