[BUG] Reaching the 5-hour session limit kills in-flight workflow agents instead of pausing them

Finding: In an external report on Claude Code 2.1.281 (Windows 11, desktop app Code tab), reaching the 5-hour session limit during a Workflow run caused still-running agents to fail with a session-limit message instead of pausing, contrary to the reporter's reading of the 2.1.271 changelog (https://github.com/anthropics/claude-code/issues/98299). The reporter says 26 in-flight agents failed on 2026-09-28. Agents that had already finished stayed saved, and resumeFromRunId after the reset re-ran only the failed ones, so no finished work was lost but the resume was manual. The reporter marks it as never working, not a regression. A second user reported the same pattern on macOS (desktop app, Code tab) on 2026-10-07: four agents running at the limit failed, and the run returned without continuing after the reset; the usage summary showed 38 agents, 34 done and 4 errors (https://github.com/anthropics/claude-code/issues/98299#issuecomment-6038211062). A third commenter on 2026-10-10 reported the same coordination problem in a custom runner of Claude Code agent subprocesses (https://github.com/anthropics/claude-code/issues/98299#issuecomment-6092431902). The reporter also says plain background agents have no pause at the limit. Cause: UNKNOWN. No maintainer response or confirmed cause appears in the supplied thread, and the expected pause behavior comes from the reporter's citation of the changelog, which was not verified here. Fix status: none reported. The reporter says no changelog entry through 2.1.285 mentions a fix; no fix commit or released fix is in the supplied sources. User-reported mitigations (not verified): resume with resumeFromRunId after the reset. The macOS commenter built a stop into the workflow script: a low-effort agent reads session usage, a semaphore does the check at agent start (parallel() queues all tasks at once), and a stop threshold below 100% (95%), because running agents keep spending. The third commenter uses a similar semaphore with a 90% threshold and keeps state files outside .claude/. Limitations: these are external reports only, with no KFA reproduction. Reproducing requires exhausting the usage limit on purpose, and the versions beyond 2.1.281 are untested by the reporter. The workarounds are partial.