chore(release): prepare 2026.9.2

[Astro-Han]

Bumps the desktop version to 2026.9.2 so the release tag has a version to build.

What ships in 2026.9.2

Both fixes address the same breakage from two sides: DSH 0.1.2-alpha dropped exports that installed community plugins still import, and upstream has not uniformly caught up.

• A plugin that fails to load can now be removed (fix(desktop): offer the plugin removal button when a plugin fails to load #1625) — a plugin whose load throws left no removal control, so the only way out of a crash loop was editing the plugin directory by hand.
• An outdated community market is upgraded before DSH loads it (fix(desktop): upgrade an outdated community market before DSH loads it #1626) — stale market entries are refreshed ahead of load, so a plugin pinned to a version that no longer resolves against DSH does not take the app down with it.

The plugins that expose this in the wild: dsh-better-sidebar still references settingsNamespace as of 0.17.1 with no adapted release, and dsh-plugin-subscriptions only added a compat shim in 0.6.0 (0.5.3 still references CallId).

No code changes since 2026.9.1 beyond these two; #1627 was documentation and website copy only.

Verification

CI on this branch, plus the pre-publish CDP pass over all six OpenCode Free models on the signed, notarized packaged build (not a dev build), per the release checklist. Results are reported on the release before it leaves draft.

[github-actions]

Suggested priority: P2 (includes non-doc, non-test paths outside the low-risk bucket).

P1/P0 are reserved for maintainer confirmation. Please relabel manually if this is a release blocker, security issue, data-loss risk, or updater/runtime failure.