Custom server URLs

[t1]

Parent: #13 (Multi-server support)

Depends on: #39 (Global server selector panel)

Add "+ Add custom URL" button to the server panel, allowing users to type arbitrary base URLs.

Scope

"+ Add custom URL" button:

• Adds a new radio option with an editable URL text field
• Consistent with the existing "add custom header" pattern
• Custom URLs can be deleted (delete button per entry)

JS:

• Add/delete custom URL entries
• On selection, update data-base-url and header display
• Persistence of custom URLs in localStorage

Design spec

See docs/superpowers/specs/2026-04-11-issue-13-multi-server-support-design.md

[t1]

Agent: starting work

Type: Feature
Summary: Adds "+ Add custom URL" button to the server selector panel, following the existing "add custom header" pattern. Users can create arbitrary custom server URLs with editable text fields, delete them, and have them persist in localStorage.

Design decisions:

• "+ Add custom URL" button placed at the bottom of the server panel (below global servers and override slot)
• Custom URLs rendered as radio buttons with editable text inputs (consistent with custom headers pattern)
• Each custom URL gets a delete button
• Custom URLs stored in localStorage and restored on page load
• When selected, updates data-base-url and the header display

Acceptance criteria:

• "+ Add custom URL" button present in server panel
• Clicking creates a new radio + text input row
• Text input editable and updates radio value on change
• Delete button removes the custom URL row
• Custom URLs persist across page reloads via localStorage
• Selecting custom URL updates base URL for try/httpie/curl

Files:

• core/src/main/java/com/github/t1/openapi/ui/generator/OpenApiUiGenerator.java (add button to serverSelector())
• core/src/main/resources/com/github/t1/openapi/ui/generator/app.js (add/delete/persist logic)
• core/src/main/resources/com/github/t1/openapi/ui/generator/app.css (styling for custom URL inputs)
• core/src/test/java/com/github/t1/openapi/ui/generator/BrowserTest.java (tests for custom URL behavior)

[t1]

Agent: done

Commit: 2505ec7
Summary: Implemented custom server URL support with "+ Add custom URL" button in the server selector panel. Users can add arbitrary server URLs with editable text inputs, delete them via delete buttons, and all custom URLs persist in localStorage. Custom URLs can be selected like regular servers and update the base URL for try/httpie/curl requests. Follows the same UI pattern as custom headers for consistency.
Tests: Added 9 comprehensive tests covering button presence, row creation, text input, delete functionality, persistence in localStorage, restoration on reload, selection behavior, and base URL updates. All 427 tests in the core module pass.
CI: passed