feat(sidebar): Drag to reorder nav items in customize dialog

[charlesvien]

Problem

The customize sidebar dialog lets you show or hide nav items, but their order is fixed.

Changes

Adds a drag handle to each row in the customize dialog. Dragging reorders the list live, persists the order and the sidebar nav renders in that order (hidden items keep it under More too). A canceled drag restores the order from dragstart. Reorders fire a new "Sidebar reordered" event. Stored order is sanitized on rehydrate and newly shipped items fall back to their default position.

How did you test this?

Unit tests for the order helpers, store rehydration and the dialog drag handlers (116 sidebar tests pass), plus typecheck and Biome. Not exercised in the running app.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

[charlesvien]

• feat(sidebar): Drag to reorder nav items in customize dialog #3670 👈 (View in Graphite)
• feat(sidebar): Add More tab, customization and click tracking #3412
• main

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[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 4265c4c.}

[greptile-apps]

Prompt To Fix All With AI

Fix the following 3 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 3
packages/ui/src/features/sidebar/constants.ts:115-116
**Repeated Hover Reverses The Move**

`dragover` can fire repeatedly while the pointer remains over one target, but this move is not idempotent. Moving adjacent `A` onto `B` first produces `[B, A]`; the next event with the same source and target restores `[A, B]`, so rows can oscillate and the persisted drop order depends on the number of pointer events.

### Issue 2 of 3
packages/ui/src/features/sidebar/constants.ts:97-102
**New Items Lose Default Position**

Every ID missing from a stored order receives a position after all stored IDs. Once an existing user has dragged and persisted the current full list, a newly shipped item inserted in the middle of `CUSTOMIZABLE_NAV_ITEMS` is therefore rendered at the end instead of its default position, giving existing users the wrong navigation order.

### Issue 3 of 3
packages/ui/src/features/sidebar/components/CustomizeSidebarDialog.tsx:83-90
**Unmount Leaves Intermediate Order Persisted**

Each hover immediately writes an intermediate order to the persisted store, while restoration exists only in `handleDragEnd`. If the dialog closes or its provider unmounts during an active drag before that callback runs, the last hover position remains saved even though the drag was never dropped.

_{Reviews (1): Last reviewed commit: "add drag to reorder nav items in customi..." | Re-trigger Greptile}

[trunk-io]

😎 This pull request was merged.

[github-actions]

Contained UI/store feature (drag-to-reorder sidebar items), no risky territory touched; the three prior Greptile findings (oscillating dragover, new items losing position, intermediate order persisting on unmount) are each fixed in the current diff with matching new tests, and the author has strong familiarity with this code.

• Author wrote 100% of the modified lines and has 23 merged PRs in these paths (familiarity STRONG).
• 👍 on the PR from greptile-apps[bot].

Gate mechanics and policy version

Gate		Result
prerequisites	✓	all clear
deny-list	✓	no deny categories matched
size	✓	270L, 5F substantive, 569L/9F incl. docs/generated/snapshots — within ceiling
tier	✓	T1-agent / T1d-complex (569L, 9F, single-area, feat)
stamphog 2.0.0b3		.stamphog/policy.yml @ f3e4b42 · reviewed head 4265c4c