fix(server): skip --resume on first headless query

[dimakis]

Summary

• Headless sessions (POST /api/sessions with initialPrompt) passed the Mitzo worktree ID as --resume to the Claude Code SDK, which rejects non-UUID values — causing 100% failure on all headless dispatch (PR Shepherd, etc.)
• Fix: omit resume on the first headless query since no SDK session exists yet. The UUID is captured via updateSessionSdkId() after the first assistant message and used for subsequent queries.
• Design doc: local_features/headless-session-resume/design.md (in mgmt)

Test plan

• Structural test: headless startChat() call omits resume option
• Structural test: interactive resume path still resolves SDK session ID via getSessionSdkId()
• Manual: POST /api/sessions with initialPrompt → first query succeeds
• Manual: PR Shepherd dispatch creates sessions that run the skill
• Manual: user reply from phone resumes the SDK session correctly

🤖 Generated with Claude Code

[dimakis]

Centaur Review

Found 2 issue(s) (1 warning).

server/__tests__/chat.test.ts

Correct one-line fix (removing resume: wtId for first headless query). The logic is sound and well-commented, but the tests rely on fragile source-code string scanning rather than behavioral assertions.

• 🟡 style (L473): Source-code-scanning tests (reading app.ts/chat.ts as strings and asserting on substrings) are fragile — any refactor that changes whitespace, variable names, or call structure will break them silently or produce false positives. The indexOf(');', startChatIdx) heuristic fails if the options object contains a nested ); sequence (e.g. in a comment or string). Consider testing the actual behavior (e.g. mock startChat and assert the options it receives) rather than parsing source text.
• 🔵 missing_tests (L492): The second test ('interactive resume path still resolves SDK session ID') duplicates the existing test at line ~346 which already asserts chatSource.toContain('getSessionSdkId(BASE_REPO, options.resume)'). This is redundant coverage — both read chat.ts source and check the same substring. [fixable]

[dimakis]

🟡 style: Source-code-scanning tests (reading app.ts/chat.ts as strings and asserting on substrings) are fragile — any refactor that changes whitespace, variable names, or call structure will break them silently or produce false positives. The indexOf(');', startChatIdx) heuristic fails if the options object contains a nested ); sequence (e.g. in a comment or string). Consider testing the actual behavior (e.g. mock startChat and assert the options it receives) rather than parsing source text.

[dimakis]

🔵 missing_tests: The second test ('interactive resume path still resolves SDK session ID') duplicates the existing test at line ~346 which already asserts chatSource.toContain('getSessionSdkId(BASE_REPO, options.resume)'). This is redundant coverage — both read chat.ts source and check the same substring. [fixable]

[dimakis]

Centaur Review

Found 1 issue(s).

server/app.ts

Correct fix — the headless path was passing a worktree ID as a resume token before any SDK session existed, which would cause the SDK to reject the query. The test follows an established source-scanning pattern in this repo. LGTM with a minor comment verbosity nit.

• 🔵 style (L483): The 4-line comment explaining why resume is omitted is helpful for the initial commit but may become noise long-term. A single line like // First query — no SDK session to resume yet would suffice given that the commit message and the updateSessionSdkId call site already document the lifecycle. [fixable]

[dimakis]

🔵 style: The 4-line comment explaining why resume is omitted is helpful for the initial commit but may become noise long-term. A single line like // First query — no SDK session to resume yet would suffice given that the commit message and the updateSessionSdkId call site already document the lifecycle. [fixable]