Add recents global nav action

[k11kirky]

Problem

Frequently revisited tasks and canvases need a fast, global way back without navigating through individual spaces.

Changes

• Add a customizable Recents action to both global navigation layouts with the same hover-card behavior as Activity.
• Show the 20 most recently viewed or actively used tasks and canvases, with direct navigation.
• Persist engagement through PostHog's user-scoped desktop file-system view history so recents follow the signed-in user across clients.

Why: Recent work should remain one hover or click away wherever someone is in the app.

How did you test this?

• Core recents and dashboard service unit tests
• Sidebar and Channels nav component tests
• Core, host-router, and UI typechecks
• Desktop and web host typechecks
• Biome checks and host-boundary validation

Automatic notifications

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

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Created with PostHog Code

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[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 2dbf48b.}

[greptile-apps]

Recents failures lack diagnostics

Every engagement write uses a void, fire-and-forget mutation with no error handler, so authentication, connectivity, missing-canvas, and backend failures leave recent items absent without any user feedback or diagnostic signal.

Rule Used: Always wrap asynchronous calls that may fail, such... (source)

Learned From
PostHog/posthog#32098

Prompt To Fix With AI

This is a comment left during a code review.
Path: packages/ui/src/features/recents/useRecents.ts
Line: 23-27

Comment:
**Recents failures lack diagnostics**

Every engagement write uses a void, fire-and-forget mutation with no error handler, so authentication, connectivity, missing-canvas, and backend failures leave recent items absent without any user feedback or diagnostic signal.

**Rule Used:** Always wrap asynchronous calls that may fail, such... ([source](https://app.greptile.com/posthog-org-19734/-/custom-context?memory=df81f021-48c3-45e4-981f-7348133f5f7a))

**Learned From**
[PostHog/posthog#32098](https://github.com/PostHog/posthog/pull/32098)

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For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

[greptile-apps]

Prompt To Fix All With AI

### Issue 1
packages/ui/src/features/recents/useRecents.ts:23-27
**Recents failures lack diagnostics**

Every engagement write uses a void, fire-and-forget mutation with no error handler, so authentication, connectivity, missing-canvas, and backend failures leave recent items absent without any user feedback or diagnostic signal.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "refactor: back recents with server engag..." | Re-trigger Greptile}

[veria-ai]

PR overview

All previously flagged issues have been addressed. No open security concerns remain on this pull request.

Security review

No open security issues remain on this pull request.

Fixed/addressed: 1 · PR risk: 0/10

[posthog]

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