[wrangler] Add User-Agent header to remote dev inspector WebSocket connections

[petebacondarwin]

Fixes #4529.

When running wrangler dev --remote, the inspector WebSocket connection to /cdn-cgi/workers/preview/inspector now includes a User-Agent header (wrangler/<version>). This resolves issues where WAF rules blocking empty User-Agent headers prevented remote dev mode from working with custom domains.

Changes

• Pass WRANGLER_VERSION binding to the InspectorProxyWorker (the binding was already defined in the Env interface but wasn't being passed)
• Add User-Agent header to the WebSocket upgrade request in InspectorProxyWorker.ts

This follows the existing pattern used for tail logs WebSocket connections in RemoteRuntimeController.ts.

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• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because: This is a minimal change that follows existing patterns. The fix adds a header to an existing WebSocket request. Existing tests pass and manual verification would require a WAF rule setup.
• Public documentation
  • Cloudflare docs PR(s):
  • Documentation not necessary because: This is an internal implementation detail fix that doesn't change any user-facing API or behavior.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 5102a16

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

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[claude]

Claude finished @petebacondarwin's task —— View job

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Changeset Review

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Review Result

✅ All changesets look good

The changeset .changeset/user-agent-remote-dev.md is well-written and follows all guidelines:

• ✅ Version Type: patch is correct - this is a bug fix addressing WAF blocking issues
• ✅ Changelog Quality: Clear, meaningful description with good context about when the issue occurs and what it fixes
• ✅ Markdown Headers: No h1/h2/h3 headers used
• ✅ Analytics: No analytics changes in this PR
• ✅ Format: Follows the recommended format with a concise title and explanatory body paragraph

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commit: 5102a16

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 4 additional findings.