fix(goal): tolerate vanished-session message windows, surface loop failures - #283

…ilures

Root cause of the invisible goal stall: the afterIdle evaluation died on a
typed NotFoundError from the messages-window read (session row gone mid-goal,
or a synthetic session), and the fork's bare Effect.ignore swallowed it —
goal left permanently active, turns_used frozen at 0, zero logs.

- afterIdle + zombie probe + post-judge reload: NotFoundError on any of the
  three messages windows degrades to an empty window (MessageV2.stream
  pattern) so the existing visible branches handle it (pause / continuation)
- triggerEvaluation fork: Effect.ignore -> catchCause + logWarning (interrupts
  stay silent per F1) so future evaluation failures are diagnosable
- judge chain: orElseSucceed -> catchCause so DEFECTS in the production
  provider chain (config orDie, payload decode) fold into the parseFailed
  budget instead of silently killing the evaluation
- auto-pause transcript line: ignore -> catchCause + logWarning (symmetric
  with the done branch)
- P2-B comment corrected: effect v4 Effect.ignore absorbs defects too;
  catchCause's value here is diagnosability, not subscription survival
- regression tests: production-wiring probe (bootstrap-wiring.test.ts),
  pre-judge window pause, post-judge reload tolerance (GOAL-FP-01-18),
  judge-defect budget degradation (GOAL-FP-01-18b)
- lint: new code is warning-neutral; drop 11 pre-existing unused imports to
  restore gate margin (oxlint ratchet, local 4846 -> 4829)