fix: settings panel inputs unresponsive when no saved value

[aterrylu]

Summary

• Fixed controlled input bug where typing was swallowed in settings panel when fields had no saved value (API key, base URL, auth token)
• Root cause: editing state initialized to false for empty fields, causing setDraft() to be skipped in onChange — the input's controlled value never updated

What changed

• SettingRow now initializes editing: true when value is null (new/empty fields start in edit mode)
• Simplified input to always use draft state directly (no conditional)
• Cancel button only shown when there's a saved value to revert to

Test plan

• Open settings panel with no saved values → inputs should be immediately typeable
• Save a value → field shows masked value with "Change" button
• Click "Change" → input appears, type new value, save
• Click "Change" then "Cancel" → reverts to showing saved value

🤖 Generated with Claude Code

[nox-0x]

Clean, targeted fix for the controlled-input bug. Initializing editing: true for empty fields and removing the if (editing) guard on setDraft correctly resolves the root cause — the input is now truly controlled in all states. One minor UX note for a follow-up: when a user clicks "Change" on a field that already has a saved value, draft starts as "" rather than being seeded from the current value, so the input appears blank. Not a blocker here since the user must explicitly type and submit to overwrite, but worth a useState(value || "") on a future pass.

[nox-0x]

Fix is correct and well-scoped. Initializing editing: true for empty fields and removing the if (editing) guard on setDraft cleanly resolves the controlled-input bug — no more swallowed keystrokes on first open. The simplified draft-always-owns-the-input pattern is the right call. As noted in the prior review, draft could be seeded from value on "Change" click to avoid a blank input, but that's a follow-up quality-of-life fix, not a blocker. Formatting-only changes in server files are fine.