[BUG] Session auto-naming stopped after Claude Desktop update — sessions stay "Untitled session" (Desktop 1.22209.0, macOS)

What happened

After updating the Claude Desktop app (macOS), new sessions no longer get an auto-generated title. They stay as "Untitled session" in the Recents sidebar until I manually rename them. Auto-naming worked reliably before this update — titles used to be generated from the conversation content shortly after a session started.

When it started

Immediately after the Desktop app auto-updated (~2026-07-16/17). No config or settings changes on my end. Restarting the app does not restore auto-naming.

Environment

• Claude Desktop app: 1.22209.0 (Claude.app/Contents/Info.plist last modified 2026-07-16)
• Claude Code CLI: 2.1.212 (unchanged before and after — claude --version)
• macOS: 26.5.2 (build 25F84)

The CLI version is unchanged across the regression, so the break appears to be in the Desktop app layer / its bundled Claude Code integration, not the standalone CLI.

Expected

Sessions auto-generate a descriptive title from conversation content shortly after they start (prior behavior).

Actual

Sessions remain "Untitled session" indefinitely; only a manual /rename produces a title.

Workaround

/rename (no argument) generates a title on demand, per session.