fix(deploy-control): stabilize empty deployments selector

[cszhouwei]

Summary

• DeployControl selector (s) => selectActiveTask(s)?.deployments ?? [] allocated a fresh [] on every render when the active task had no deployments, so zustand's default Object.is snapshot comparison saw a new value each time.
• That triggered the React warnings getSnapshot should be cached to avoid an infinite loop and Maximum update depth exceeded, surfacing in the preview pane the moment <DeployControl /> mounted for a task without prior deployments.
• Fix: hoist a module-level EMPTY_DEPLOYMENTS: readonly DeploymentRecord[] constant and return it from the selector so the snapshot reference is stable.

Test plan

• Open a fresh task (no prior deploys) and confirm <DeployControl /> renders without the React error overlay.
• Run a deploy → verify the success row + history dropdown still work, and the deployments count updates as before.
• Switch between tasks (one with deploys, one without) and confirm no render loop is triggered.

🤖 Generated with Claude Code

[lefarcen]

Heads-up: #37 is now open and also touches src/components/deploy-control.tsx for the empty deployments selector fallback behind #32. This PR is the focused bugfix, while #37 includes that stabilization as part of a larger per-task history feature.

You and @wuwangzhang1216 may want to compare scope; the maintainer team will decide which path lands so neither effort gets wasted.

[lefarcen]

Adding one more coordination note: PR #25 is also open against this same DeployControl empty-deployments selector loop. Both PRs make the fallback reference stable in src/components/deploy-control.tsx, with #31/#32 carrying the user-facing error reports.

The maintainer team will choose which focused fix to land; noting the overlap so everyone has the full picture.

[lefarcen]

Heads-up: PR #41 is now also open against this same DeployControl selector loop. Both PRs touch src/components/deploy-control.tsx and use a shared empty deployments array to avoid the unstable deployments ?? [] fallback.

You and @jidechao may want to compare approaches; the maintainer team will decide which one lands. Sharing this so neither effort gets wasted.

[lefarcen]

Adding one more coordination note: PR #42 is now also open against this same DeployControl selector loop. It touches src/components/deploy-control.tsx and uses the same stable empty deployments fallback direction as the focused fixes here and in #41.

The maintainer team will choose which focused fix lands; noting the overlap so everyone has the latest picture.

[joeylee12629-star]

LGTM. Cleanest of the four duplicates — readonly type + module-scope constant fixes the getSnapshot infinite loop without touching the selectActiveTask helper.