fix: address 5 SDK compatibility issues from Cubic round 8

- P1: Use compacted timestamp check instead of nonexistent truncated
  field in target-token-truncation.ts
- P1: Use defensive (response.data ?? response) pattern in
  hook-message-injector/injector.ts to match codebase convention
- P2: Filter by tool type in countTruncatedResultsFromSDK to avoid
  counting non-tool compacted parts
- P2: Treat thinking/meta-only messages as empty in both
  empty-content-recovery-sdk.ts and message-builder.ts to align
  SDK path with file-based logic

src/hooks/anthropic-context-window-limit-recovery/message-builder.ts

@@ -51,8 +51,9 @@ function messageHasContentFromSDK(message: SDKMessage): boolean {
     return true
   }
 
-  // Messages with only thinking/meta parts are NOT empty — they have content
-  return hasIgnoredParts
+  // Messages with only thinking/meta parts are treated as empty
+  // to align with file-based logic (messageHasContent)
+  return false
 }
 
 async function findEmptyMessageIdsFromSDK(