[Local-Explorer-UI] Add Workflows support

[pombosilva]

Fixes WOR-1197.

• Adds Workflows as a new resource type to the local explorer (/cdn-cgi/explorer/), replicating the production Cloudflare dashboard Workflows pages for local development
• Implements a full workflow instance management dashboard with instance listing, detail views, step history visualization, and instance lifecycle actions
• Adds 9 new API endpoints to the explorer worker for workflow CRUD and instance management
  • GET /workflows — list all workflows
  • GET /workflows/:name — get workflow details with instance status counts
  • GET /workflows/:name/instances — list instances with server-side pagination, sorted by creation time
  • GET /workflows/:name/instances/:id — get instance details including step history
  • POST /workflows/:name/instances — create a new instance with optional ID and params
  • PATCH /workflows/:name/instances/:id/status — change instance status (pause/resume/restart/terminate)
  • DELETE /workflows/:name/instances/:id — delete a single instance
  • DELETE /workflows/:name — delete all instances of a workflow
  • POST /workflows/:name/instances/:id/events/:type — send an event to an instance
• The @cloudflare/workflows-shared package adds getInstanceMetadata() and readDetailedLogs() methods to the Engine DO, and populates created_on in instance metadata during creation.

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• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because: they will be added later on
• Public documentation
  • Cloudflare docs PR(s):
  • Documentation not necessary because: WIP Experimental feature

A picture of a cute animal (not mandatory, but encouraged)

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[changeset-bot]

🦋 Changeset detected

Latest commit: 7d0f52d

The changes in this PR will be included in the next version bump.

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[github-actions]

✅ All changesets look good

[ask-bonk]

Everything is consistently typed and used. Now let me compile my final assessment.

After a thorough review, I found the following notable items:

1. Status counts performance on first load (getStatusCounts) - resolving all Engine DOs is O(N) on cache miss. This is documented but worth noting for large workflow sets. Not a bug per se.

2. Module-level caches (statusCountsCache, workflowOwnerCache) - These are in-memory caches in the worker context. Since the explorer worker is long-lived, these work correctly but never get cleared except on TTL or explicit invalidation. This is an acceptable design decision.

3. The timeAgo function is duplicated between Timestamp.tsx (private) and helpers.ts (exported). Minor duplication but not a bug.

4. The formatTimestamp export in helpers.ts is unused dead code. Not a bug.

5. The status as never cast in WorkflowStatusBadge usage is a minor type-safety concern but works.

The code overall is well-structured, follows the existing patterns for other resource types (KV, D1, DO, R2), has proper error handling, directory traversal protection, and correct enum value mappings. The engine changes are minimal and safe (read-only methods added to an existing DO).

I don't see any logic bugs, security issues, backward compatibility violations, or incorrect API behavior that would warrant actionable review comments.

LGTM

github run

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@cloudflare/pages-shared

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wrangler

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commit: 7d0f52d

[workers-devprod]

Codeowners approval required for this PR:

• ✅ @cloudflare/workflows
• ✅ @cloudflare/wrangler

Show detailed file reviewers

[avenceslau]

Besides the bot's comments everything looks good to me

[petebacondarwin]

LGTM - I pulled down the code and played with it locally using the fixtures/workflows Worker. Couldn't find any issues with the UI or UX. Nice stuff.