fix(channel): restore thread reply fetch debounce

[synoet]

What changed

• Restore a 300 ms cold-start debounce before channel thread reply queries become enabled.
• Keep the immediate path only for the currently targeted reply while the channel Cmd+F find bar is open.
• Cancel pending debounce timers when transiently mounted threads unmount.

Why

PR #3305 unintentionally removed the existing reply-fetch debounce while optimizing in-channel search. That allowed transiently mounted virtualized threads to enable reply queries immediately. Normal expansion and non-search deep-link navigation are now debounced; Cmd+F retains immediate targeted-reply navigation.

Validation

• bunx vitest run src/features/channel/Thread/tests — 27 tests passed
• bun run check — type-check and Biome passed

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 563575cf-effd-4abb-974e-79cb8fb2f955

📥 Commits

Reviewing files that changed from the base of the PR and between 816d9b1 and 49c77a4.

📒 Files selected for processing (6)

• apps/web/src/features/channel/Channel/Channel.tsx
• apps/web/src/features/channel/Thread/ChannelThread.tsx
• apps/web/src/features/channel/Thread/create-thread-replies-fetch-gate.ts
• apps/web/src/features/channel/Thread/tests/create-thread-replies-fetch-gate.test.ts
• apps/web/src/features/channel/Thread/types.ts
• apps/web/src/lib/core/util/debounce.ts

---

📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes
  • Improved thread reply loading while using the channel find bar.
  • Added a brief delay to prevent unnecessary reply fetches during temporary thread navigation or expansion.
  • Canceled pending reply loads when threads are closed or unmounted.
• Tests
  • Added coverage for delayed loading, immediate find-bar navigation, and cleanup behavior.

Walkthrough

Channel threads now receive the channel find-bar state and use a dedicated reactive gate for reply fetching. The gate immediately enables targeted replies while the find bar is open and debounces expanded, targeted, or high-count thread fetches. The deferred gate is exported and cancels pending timers on scope disposal. Tests cover debounce timing, immediate find-bar targeting, and cleanup on unmount.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title follows conventional commits format and clearly summarizes the debounce restoration.
Description check	✅ Passed	The description is directly related to restoring thread reply fetch debounce behavior and validation.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

Preview: https://agent-restore-channel-thread-f-m3i3gw.preview.macro.com/app (777fcce)