Anthropic HTTP 500 errors surface in the TUI with payloads containing
"rate limit" text, which the monitor was matching against quotaPatterns
and treating as a real 429 quota hit. With no cooldown and no
confirmation, a burst of 500s produced sub-minute ping-pong swaps that
tore down user sessions.
Two-layer fix:
- quota.reactivate_cooldown (already in config, 5m) now gates the
monitor too — not just the dispatcher. A completed swap suppresses
further detection for the cooldown window.
- A hit with no parseable reset time is treated as suspected only on
the first poll; a second consecutive poll is required before
emitting SwapRequested. Legitimate 429s with "resets in ..." still
swap instantly on the first detection.
Adds state.RecordSwap / LastSwapInfo for the cooldown, and a
forensic log line on every detection: trigger_session, matched
pattern, 120-char pane snippet.
Tests cover: instant swap with reset, 2-poll confirmation without
reset, and suspected-state reset on recovery.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>