fix(desktop): show an agent in @ search after you add it to a channel

[loganj]

🤖

Summary

An old agent list could hide an agent from Add members after you created a channel. Buzz now refreshes the list after channel creation. When Add succeeds and the server returns the new membership, the agent can appear in your first @ search. You do not need to restart the app or refresh the list by hand.

Welcome starter creation now refreshes the affected composer member roster at both provisioning completion paths. Otherwise its five-minute cached list can recognize only an older same-name Fizz and publish to it instead of rejecting ambiguity. The regression checks both exact member keys, then preserves the no-send/draft and exact-selected-starter flow.

Buzz also requests a refresh after successful join and leave actions. A later membership list can trigger another refresh if the server did not show the change at first. This does not make server updates immediate or grant an agent access.

Action or result	What Buzz does
Create, join, or leave succeeds	Requests new agent information
Add accepts at least one member	Requests new agent information
Add accepts no members	Does not refresh for that result alone
A later list changes members, roles, or whether a member is an agent	Requests new agent information
The first membership list contains an agent	Requests new agent information
Only names or order change, or the same list arrives again	Does not request an extra refresh

This is draft PR 3 of 7, based on #7191, which follows #7190. New access labels and checks on old selections are separate changes.

Related issue

Follow-up to #7122 and #7124. The shared base, 802ba6170e57ac71d1ecfd6cf6fb12f02ecf910c, includes the required agent search, sending, spacing (#7128), and recipient identity (#7133) changes on main revision 114dbf745f1fe0bdbecb70e07a07f03c23687bdc. Those dependencies are not this PR's own change. Separate forum and unrelated timeline work are excluded.

Testing

• This repaired prefix 07fbd2ccb354c9ab81b018811f9799cbb00901a7 passed a fresh TypeScript/E2E build, 6/6 Welcome/onboarding browser cases and 51/51 focused tests (welcome guide/kickoff, roster freshness, membership journey). The earlier 68 packaging tests apply to the old prefix.
• Integrated onboarding repair: fresh build passed; 6/6 Welcome browser cases and 129/129 focused tests passed. The strengthened cached-roster regression fails against the old production build and passes against the repair, before exercising the original ambiguous-name/no-send/draft/exact-starter assertions.
• Final integrated production (unchanged by the additional test-only PR5 delta) passed 9/9 send-binding and agent-control browser cases, including Stop rejecting the foreign-channel result. Final TypeScript, four-file Biome and differential size checks passed. The earlier remote Stop timeout is not established as a picker defect; no control product/test change was made.
• The old published seven-slice tree aa90290870119e0bef2ba5ebcb6ce92c069db388 passed 165 affected Chromium cases, 161 focused tests and five bounded ordinary Enter/code-fence/multiline/emoji controls. Those results are reused for unaffected scope, not claimed as fresh whole-stack tests of this head. Historical 6,122 desktop tests predate the earlier Enter repair. Full repository just ci was not repeated.
• Browser checks use simulated desktop services: no native/WebKit, live-relay acceptance/delivery, or atomic access-check/publication claim. The exact-head CI result is recorded below; old-head onboarding/send-binding failures and canceled duplicate runs are not current-source failures.
• Immediate base: 9164074d7be6608a8a83172f3a13b33782c51928. Head: 07fbd2ccb354c9ab81b018811f9799cbb00901a7. Footprint including tests: 607 additions + deletions. Fixed stack root: 802ba6170e57ac71d1ecfd6cf6fb12f02ecf910c.

The following are preserved historical captures, not new-head screenshots. Their revision captions and immutable URLs are retained.

Before: Add members cannot find the agent

At the parent revision, 21349006, the app already has an old agent list. Creating a channel does not refresh that list. Add members finds no matching agent. This image does not show a successful Add.

After: Add succeeds and the first @ search finds the agent

At the earlier revision shown here, c0da14c8, the same search finds Fresh Scout. Add succeeds. The first @Fresh search shows Fresh Scout as a channel member. This PR does not include the later Member and Invite labels.

Exact-head CI follow-through (2026-09-02)

• CI run completed successfully for 07fbd2ccb354c9ab81b018811f9799cbb00901a7: 14 successful jobs, 10 path/condition-skipped jobs. This is the path-scoped remote workflow result, not a new claim that every repository test ran.
• Draft remains open; native/WebKit behavior, live-relay acceptance/delivery and atomic access-check/publication are not established by mock-browser checks.

Origin discussion: Buzz channel 8dcd7afb-0193-4a3e-8ae9-72838de89a1d; original source channel f7a9536a-1738-4bad-a888-b3ea25010ef1. Draft only; no merge authority.

[loganj]

🤖

Before: preceding prefix cannot find the agent in Add members

Actual 21349006 build, warm-stale directory. Search is blocked; no successful Add is claimed.

After: Add succeeds and the first @ picker includes the agent

Actual c0da14c8 build, same fixture. Fresh Scout is present after Add, without a manual directory refresh.