Fix session persistence and auto-start container system

- Fix session mount path: ~/.claude/ now mounts to /home/node/.claude/
  (container runs as 'node' user with HOME=/home/node, not root)
- Fix ~/.gmail-mcp/ mount path similarly
- Use absolute paths for GROUPS_DIR and DATA_DIR (required for container mounts)
- Auto-start Apple Container system on NanoClaw startup
- Update debug skill with session troubleshooting guide
- Update spec.md with startup sequence and troubleshooting

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

container/agent-runner/src/index.ts

@@ -111,12 +111,13 @@ async function main(): Promise<void> {
     });
 
   } catch (err) {
-    log(`Agent error: ${err instanceof Error ? err.message : String(err)}`);
+    const errorMessage = err instanceof Error ? err.message : String(err);
+    log(`Agent error: ${errorMessage}`);
     writeOutput({
       status: 'error',
       result: null,
       newSessionId,
-      error: err instanceof Error ? err.message : String(err)
+      error: errorMessage
     });
     process.exit(1);
   }