Fix focus change re-renders

[samhh]

Currently blocked from merging by this: #15612 (comment)

If someone with elevated permissions would like to merge please go ahead. 🙂

[Copilot]

Pull request overview

This PR aims to reduce unnecessary re-renders in the Lite workspace UI (notably those triggered by focus changes) by removing focus-driven subscriptions and by replacing several array-building patterns with iterator-based pipelines to reduce intermediate allocations and identity churn.

Changes:

• Remove the useActiveElement focus subscription and compute focused scope at the time a hotkey is invoked.
• Replace many flatMap/array-materialization patterns with iterator pipelines (values(), map, filter, toArray) and add small iterator utilities (reverseValues, iteratorConcat).
• Export a couple of previously-internal types (CheckableAddress, CheckedConflict) to support new typing needs across workspace components.

Reviewed changes

Copilot reviewed 29 out of 29 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
apps/lite/ui/src/routes/project/$id/workspace/WorkspaceLists/WorkspaceLists.tsx	Switch stack/changes/address derivations to iterator pipelines; reverse stack traversal without cloning.
apps/lite/ui/src/routes/project/$id/workspace/WorkspaceLists/useStackMenuItems.ts	Build foldable ref list via iterators to avoid intermediate arrays.
apps/lite/ui/src/routes/project/$id/workspace/WorkspaceLists/commitTargetComboboxItems.ts	Build commit-target combobox items using reversed iteration + iterator filtering.
apps/lite/ui/src/routes/project/$id/workspace/useUpstreamList.ts	Refactor stack-branch extraction into iterator pipeline; adjust call site for optional headInfo.
apps/lite/ui/src/routes/project/$id/workspace/useCheckedActions.ts	Derive selected hunks via iterator map/filter instead of flatMap.
apps/lite/ui/src/routes/project/$id/workspace/Sidebar.tsx	Compute rebase updates inside the action and build them via iterators.
apps/lite/ui/src/routes/project/$id/workspace/Page.tsx	Remove focus subscription hook usage; compute focus scope on-demand in hotkey callback.
apps/lite/ui/src/routes/project/$id/workspace/FilesTree.tsx	Convert set-building and checked-path extraction to iterator pipelines.
apps/lite/ui/src/routes/project/$id/workspace/file-row.ts	Return file-row items as an iterator (via iteratorConcat) and materialize only where needed.
apps/lite/ui/src/routes/project/$id/workspace/diff-minimap.ts	Replace flatMap with iterator map/filter/toArray for selection endpoints.
apps/lite/ui/src/routes/project/$id/workspace/diff-line-target.ts	Replace flatMap with iterator helpers to locate the first line-number attribute.
apps/lite/ui/src/routes/project/$id/workspace/Details.tsx	Refactor multiple “derive collections” spots to iterator pipelines and tighten some types.
apps/lite/ui/src/routes/project/$id/workspace/DependencyIndicator.tsx	Build dependency tooltip set via iterator map/filter.
apps/lite/ui/src/routes/project/$id/workspace/ConflictBar.tsx	Build checked conflict mapping via iterator pipeline; add exported type dependency.
apps/lite/ui/src/routes/project/$id/workspace/CommitForm.tsx	Build commit change specs via iterator filtering instead of flatMap.
apps/lite/ui/src/routes/project/$id/workspace/CommandPalette.tsx	Accept iterables for grouping and use iteratorConcat to combine filtered items.
apps/lite/ui/src/routes/project/$id/workspace/BranchPicker.tsx	Produce branch picker options via iterator pipeline and materialize once.
apps/lite/ui/src/routes/project/$id/workspace/ApplyBranchPicker.tsx	Refactor option derivation/grouping to iterator pipelines (includes one runtime-compat concern).
apps/lite/ui/src/routes/project/$id/workspace/applied-address-space.ts	Use reverseValues to walk stacks in reverse without toReversed() cloning.
apps/lite/ui/src/routes/project/$id/workspace/AnnotationCard.tsx	Replace flatMap-based filtering with a type-narrowing filter.
apps/lite/ui/src/router.ts	Refactor query-string building to iterator filter/map/toArray pipeline.
apps/lite/ui/src/reconcile.ts	Refactor multiple checked-item derivations and query combine logic to iterators.
apps/lite/ui/src/projects/project.ts	Export CheckableAddress and CheckedConflict types for cross-module use.
apps/lite/ui/src/project-events.ts	Refactor integrated-review refresh collection building to iterator pipeline.
apps/lite/ui/src/native-menu.ts	Remove @public doc comments from exported menu helpers.
apps/lite/ui/src/iterator.ts	Add iterator utilities: iteratorConcat and reverseValues.
apps/lite/ui/src/hunk.ts	Refactor selection positioning derivation to iterator map/filter/toArray.
apps/lite/ui/src/focus.ts	Remove useActiveElement hook (and its focus event subscription).
apps/lite/ui/src/checking.ts	Refactor range construction to iterator drop/take pipeline feeding Set.

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[krlvi]

@samhh sorry for the blockage. It is not fixed in the latest version of the app - so if you just rebase or edit something here, the committer will be fixed