Desktop title generation previously upgraded the first sidebar title from the raw user prompt before assistant output existed. That made image-plus-text sessions vulnerable to keeping a title based only on the user's initial wording. This moves polished title generation to completed turns, reuses the CLI title prompt and transcript extractor, and routes title calls through the configured haiku model with a retry when disabled thinking is rejected.
Constraint: The first user message still needs an immediate placeholder title so the sidebar is responsive.
Rejected: Generate the AI title before assistant output | image-derived context is only available after the assistant turn completes.
Confidence: high
Scope-risk: moderate
Directive: Keep polished automatic titles tied to completed transcript turns, not pre-response user prompts.
Tested: bun test src/server/__tests__/title-service.test.ts
Tested: bun test src/server/__tests__/conversations.test.ts -t "refreshes the first-turn AI title"
Tested: git diff --check
Tested: Real MiniMax-M3 /tmp session f89073ed-3467-492a-b63c-e1886c146a3a with image attachment wrote ai-title "Validate session title generation"
Not-tested: bun run check:server is blocked by existing expired quarantine manifest entries
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
