v0.3.7

Added

• Upstream timeout config field in dashboard. upstream_timeout_ms
  is now exposed in the dashboard's Server section (with validation:
  integer ≥ 1000ms) and serialized through the dashboard config save
  path. The field was already used by the proxy but was not previously
  editable from the UI.

• TTFT Watchdog config section in dashboard. Seven new
  experimental fields (experiment_ttft_watchdog, ttft_timeout_ms,
  ttft_retry_max_attempts, ttft_retry_gate_saturation_pct,
  ttft_retry_failure_window_ms, ttft_retry_failure_threshold,
  ttft_retry_cooldown_ms) are now editable in the dashboard under a
  new "TTFT Watchdog" group, with server-side validation rules covering
  type, minimum, and range constraints for each field.

Fixed

• Permit leak when upstream hangs after the first chunk. When the
  upstream sent some data and then stalled while the client stayed
  connected, the concurrency permit was never released — active
  climbed to the cap and stayed there until process restart, and
  captures remained stuck in state="streaming" with no terminal
  status. Root cause: onAbort listened only on req.signal (which
  does NOT abort in this scenario on Bun 1.3.14), and
  TransformStream.flush() did not fire on abnormal termination.
  Fixed by:
  • Part A — also listening on the upstream signal
    (AbortSignal.any([req.signal, ttftController?, timeout])) so
    timeout/client-abort propagated to the fetch also triggers
    flushCapture + releasePermit.
  • Part B — fixing the already-aborted req.signal branch to
    release the permit immediately (previously only flushed the
    capture).
  • Part C — adding a per-request watchdog timer
    (upstream_timeout_ms + 5s) as a safety net that fires if none of
    the other release paths run. Catches pathological cases where the
    stream errors but no signal aborts.
  • The rewrite-id retry path (attemptRewriteRetry) now returns the
    upstream signal alongside the response so callers can attach the
    same release listener for retries as for the primary fetch.
  • Regression test test/permit-leak-upstream-hang.test.ts exercises
    the exact failure mode (chunk1 sent, then hang).