* fix(api): scan to first complete exchange for title regeneration (#7543)
_first_exchange_snippets() aborted at a second consecutive user message
before collecting assistant text, so transcripts opening with queued user
rows (channel-backed imports) hit the missing_exchange rejection and the
deterministic fallback got persisted with HTTP 200 — invisible in the UI
and unrecoverable by retrying.
Keep scanning until the first complete user+assistant pair instead, and
fall back to the last complete exchange when the opening user message
yields no user text (privacy scrubbing) instead of failing with
empty_user_message.
Tests: tests/test_issue7543_title_first_exchange.py (8 cases, incl. the
issue-pinned transcript shape and walker-mocked discriminator tests for
both fixes).
* test(api): drop local-machine notes and sys.path hack from 7543 test module
- Docstring described the change as a local-only uncommitted hotfix with
machine-specific paths — wrong for an upstream PR and unsafe to publish.
- Drop the defensive REPO_ROOT sys.path insert; the repo conftest already
puts the package root on sys.path (matches the neighboring test modules).
* fix(api): drop unreachable latest-exchange fallback from title regeneration
Greptile flagged the mocked-walker fallback test (P2) as fabricating
internal state, and an exhaustive enumeration of realistic transcript
shapes (5460 combinations, lengths 1-6) confirms it: both walkers share
the same text extraction and the forward walker scans every message, so
'first walker empty while latest walker yields a pair' is unreachable
from real transcripts. The fallback branch was dead code.
Remove it together with its two walker-mocked tests; the fixed first-
exchange walker alone resolves the reported issue shape. Replace the
mocked tests with an observable E2E error-path test through the real
walkers, and make the aux mock guard-faithful (empty assistant_text ->
missing_exchange per the generate_title_raw_via_aux contract) so the
fail-before proof actually exercises the endpoint contract.
* fix(#7543): scope first-exchange scan-past to the manual-regen path only
The full suite caught that broadening the SHARED _first_exchange_snippets also
activated the automatic in-stream background-title path for consecutive-user-row
transcripts, moving stream teardown from the synchronous stream_end branch to the
background-title-thread branch (test_issue3929 emits_done regressed: stream_end
was no longer in the synchronous queue). #7543 is specifically about the MANUAL
'Regenerate title' endpoint, so gate the scan-past behavior behind an opt-in
scan_past_consecutive_users flag (default False = master behavior) and pass True
only from generate_session_title_for_session. Auto in-stream path is now
byte-identical to master; added a default-behavior regression guard test.
* docs(changelog): stamp #7545 (manual title regen for queued-user transcripts)
---------
Co-authored-by: Raylands <Raylands@users.noreply.github.com>
Co-authored-by: nesquena-hermes <nesquena-hermes@users.noreply.github.com>
Co-authored-by: n <a@n>
