Enhance custom model entry visibility

[BlueChubby]

Related issue

Closes #

Summary

Affected surfaces

• Frontend / Web
• Backend / API / Storage
• Database plugin / Driver
• JCEF / Desktop packaging
• CI / Build / Release
• Documentation only

Verification

• Commands and results:
• Manual verification:
• UI evidence: N/A

Risk and compatibility

• Public API or stored data:
• Database or driver compatibility:
• Network, privacy, or security:
• Community / Local / Pro boundary:
• Backward compatibility:

Reviewer map

• Start here:
• Failure condition:
• Rollback or disable path:

Contributor declaration

• I linked the Issue that defines this change.
• I tested the affected behavior and reported the actual results above.
• I did not include credentials, private data, or generated build output.
• I disclosed substantial AI assistance below, or this PR contains no substantial AI-generated code.

AI assistance: N/A

[openai0229]

Thanks for improving the visibility and accessibility of the custom-model entry. The code change is scoped to the frontend, the entry is now a real button, and the current frontend CI passes.\n\nBefore this can be merged, please complete the pull-request contract:\n\n1. Link the approved Issue in (the current is empty) and explain the user-visible problem this change is intended to solve.\n2. Complete every PR-template section, including the affected Frontend/Web checkbox, exact verification commands and results, risk/compatibility notes, reviewer map, and contributor declarations.\n3. Add before/after screenshots or a short recording for both dropdown states: no configured models and at least one configured model. Please include the click-through to model settings and keyboard activation of the new button.\n\nThis is necessary because the patch changes the trigger width, placeholder, dropdown width, hover/focus behavior, and the empty-state action at the same time. CI can verify compilation and linting, but it cannot establish that the intended visual behavior is correct or that the settings entry remains usable in both dropdown states. Once the Issue, completed template, and UI evidence are present, the implementation can be reviewed against a concrete expected behavior.

Formatting issue in the submitted review; replaced by the corrected review below.

[openai0229]

Thanks for improving the visibility and accessibility of the custom-model entry. The code change is scoped to the frontend, the entry is now a real button, and the current frontend CI passes.

Before this can be merged, please complete the pull-request contract:

1. Link the approved Issue in Related issue (the current Closes # is empty) and explain the user-visible problem this change is intended to solve.
2. Complete every PR-template section, including the affected Frontend/Web checkbox, exact verification commands and results, risk/compatibility notes, reviewer map, and contributor declarations.
3. Add before/after screenshots or a short recording for both dropdown states: no configured models and at least one configured model. Please include the click-through to model settings and keyboard activation of the new button.

This is necessary because the patch changes the trigger width, placeholder, dropdown width, hover/focus behavior, and the empty-state action at the same time. CI can verify compilation and linting, but it cannot establish that the intended visual behavior is correct or that the settings entry remains usable in both dropdown states. Once the Issue, completed template, and UI evidence are present, the implementation can be reviewed against a concrete expected behavior.