Best possible solution:

Land this PR after maintainer review and exact-head gates so chat delivery stays aligned with the documented live /verbose contract.

Do we have a high-confidence way to reproduce the issue?

Yes, source-reproducible: current docs require in-flight /verbose changes to affect later tool bubbles, while current main snapshots gateway run verbose and hard-suppresses preview progress in the shared delivery path. I did not run local tests because this review had to keep the checkout read-only, but the PR adds focused regression coverage.

Is this the best way to solve the issue?

Yes: the PR is a narrow maintainable fix that refreshes session verbose state only at the affected delivery points, preserves one-shot run verbose when the session is older, and adds regression tests for both gateway and channel reply paths.

What I checked:

• documented_verbose_contract: The docs say that if /verbose on|full|off is toggled while a run is in flight, subsequent tool bubbles honor the new setting. Public docs: docs/tools/thinking.md. (docs/tools/thinking.md:85, 39c5bbf08e12)
• current_gateway_snapshot: Current main returns the run-start verbose snapshot before consulting session state, so later session changes cannot override a stored run verbose value. (src/gateway/server-chat.ts:562, 39c5bbf08e12)
• current_preview_suppression: Current main treats suppressDefaultToolProgressMessages as a hard gate for tool, plan, approval, and patch progress delivery. (src/auto-reply/reply/dispatch-from-config.ts:1260, 39c5bbf08e12)
• pr_runtime_fix: The PR head changes gateway verbose resolution to prefer newer session state and changes auto-reply suppression to call shouldSuppressDefaultToolProgressMessages(). (src/gateway/server-chat.ts:562, da131b66396a)
• prior_finding_fixed: The latest PR head adds the full typed loadSessionEntry mock shape, including storePath, store, canonicalKey, legacyKey, and sessionId on non-undefined entries. (src/gateway/server-chat.agent-events.test.ts:28, da131b66396a)
• pr_checks_current_head: The GitHub check-runs API for the latest head reported zero incomplete or non-success/skipped/neutral check runs when filtered for actionable failures. (da131b66396a)

Likely related people:

• steipete: Recent merged work repeatedly touched the auto-reply delivery path and its regression tests, including lazy loader refactors, diagnostic progress tracking, and visible reply delivery fixes. (role: recent maintainer; confidence: high; commits: 59fb9e5ca7fe, 2d8d50d418a2, 1c300cec5d80; files: src/auto-reply/reply/dispatch-from-config.ts, src/auto-reply/reply/dispatch-from-config.test.ts)
• Takhoffman: Recent gateway work preserved and hydrated session/tool-event metadata on the same server-chat tool-event delivery surface touched by this PR. (role: adjacent owner; confidence: medium; commits: 9a57bdfdf14b, e890cde041f6, 8aace2b44828; files: src/gateway/server-chat.ts, src/gateway/server-chat.agent-events.test.ts)
• frankbuild: Prior merged work fixed verbose tool summary delivery in channel replies, which overlaps the auto-reply verbose-progress behavior addressed here. (role: adjacent contributor; confidence: medium; commits: 74ed75f2e74d; files: src/auto-reply/reply/dispatch-from-config.ts, src/auto-reply/reply/dispatch-from-config.test.ts)

Codex review notes: model gpt-5.5, reasoning high; reviewed against 39c5bbf08e12.