Slash-command and skill prompts can enter the title-generation path as internal XML breadcrumbs. The async title request previously treated that transport metadata as user prose, so a generated ai-title could persist raw command tags and override the normal session title.
This routes title sources and generated title output through a shared sanitizer, preserving user-visible command names and arguments while dropping unrelated internal XML metadata. Desktop fallback title rendering now applies the same cleanup so existing transcripts with bad ai-title entries recover on read.
Constraint: Session titles can be produced by both desktop server logic and the SDK generate_session_title control request.
Rejected: Only clean desktop session display | leaves CLI and remote title generation able to persist bad titles again
Confidence: high
Scope-risk: moderate
Directive: Keep generated-title input and persisted-title readback on the shared sanitizer; do not add a title path that reads command XML directly.
Tested: bun test src/utils/__tests__/sessionTitle.test.ts src/utils/__tests__/sessionTitleText.test.ts
Tested: bun run check:server
Tested: bun run check:desktop
Tested: bun run verify (7 passed, 1 failed on existing aggregate agent-utils coverage baseline)
Not-tested: live model title-generation smoke
