fix: map fqdn to domains for Coolify API compatibility

[terry90918]

Closes #126

Summary

• Coolify API uses the domains field for setting application domain, not fqdn
• Added mapFqdnToDomains helper that transparently converts fqdn → domains before sending requests
• Applied to createApplicationPublic, createApplicationPrivateGH, createApplicationPrivateKey, and updateApplication
• Callers using the fqdn field now work correctly without any breaking changes

Root Cause

When creating or updating applications with a custom domain, passing fqdn: "https://app.example.com" was silently ignored by the Coolify API because it expects the field to be named domains. This meant domain settings were never applied.

Historical Evidence

Git archaeology on coollabsio/coolify shows domains has been the correct API field since the very beginning:

Date	Commit	Event
2024-06-21	cd8509411	Applications.php created — GET endpoints only, no fqdn or domains
2024-06-28	30b7e831	domains introduced as the API input field in sharedDataApplications(). $fqdn is only an internal PHP variable ($fqdn = $request->domains) that writes to the DB column
2024-07-01	da6f2da3	extraFields strict validation introduced — passing fqdn triggers 422 "This field is not allowed"
2025-12-09	32e047e5	Bug fix: POST response was returning null for domains — fixed to data_get($application, 'fqdn')
2026-01-12	ce3cae3f	beta.461 — additional restrictions for dockercompose; domains becomes nullable

Key points:

• fqdn was never a valid API input field — sharedDataApplications() has always listed domains, never fqdn
• The accidental window was 3 days (June 28 → July 1, 2024) — fqdn accidentally worked via fill($request->all()) before strict validation was added
• domains has been correct for ~1.5 years (beta.307) — try/fallback or version detection are not needed

Design options

Option A (this PR): Keep fqdn in TypeScript types, map silently → no breaking change for existing callers

Option B: Rename fqdn → domains in CreateApplicationPublicRequest / UpdateApplicationRequest and update mcp-server.ts → types match the API exactly, helper removed. Since fqdn was always silently broken, this could be argued as a non-breaking fix.

Happy to update either way — feedback welcome.

Changes

• src/lib/coolify-client.ts — Added mapFqdnToDomains generic helper and applied it in the 4 affected methods
• src/__tests__/coolify-client.test.ts — Added 6 tests covering:
  • fqdn → domains mapping in all 3 create methods
  • fqdn → domains mapping in updateApplication
  • Combined fqdn + docker_compose_raw in updateApplication
  • No-op when fqdn is not provided
• CHANGELOG.md — Added entry under new [2.6.3] version

Test plan

• All 235 existing tests pass
• 6 new tests added and passing
• fqdn is correctly renamed to domains in request body
• fqdn key is absent from the final request body
• Requests without fqdn are unaffected

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes a bug where the fqdn field was silently ignored when creating or updating applications, because the Coolify API expects the field to be named domains instead. The fix introduces a helper function mapFqdnToDomains that transparently converts fqdn to domains before sending requests, providing backward compatibility for callers.

Changes:

• Added mapFqdnToDomains helper function to map fqdn → domains for Coolify API compatibility
• Applied the helper to 4 methods: createApplicationPublic, createApplicationPrivateGH, createApplicationPrivateKey, and updateApplication
• Added 5 comprehensive tests covering the mapping behavior

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
src/lib/coolify-client.ts	Added mapFqdnToDomains helper and applied it to 4 application create/update methods
src/tests/coolify-client.test.ts	Added 5 tests verifying fqdn → domains mapping works correctly
CHANGELOG.md	Documented the fix in version 2.6.3 release notes

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[StuMason]

Incredible @terry90918, thanks for this and for the deepdive too, really appreciate it!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.44%. Comparing base (1380736) to head (e07ea85).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #125      +/-   ##
==========================================
+ Coverage   91.33%   91.44%   +0.10%     
==========================================
  Files           1        1              
  Lines         404      409       +5     
  Branches      111      112       +1     
==========================================
+ Hits          369      374       +5     
  Misses          6        6              
  Partials       29       29              

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