* enhancement: Pin Configure Models button to bottom of model selector (#637)
Keep "Configure Models..." and info text fixed at bottom of dropdown when the model list scrolls. Wire button to open Model Config dialog.
* Address PR review: use ModelSelectorItem, z-10 footer, padding on wrapper
* fix: reduce spacing between Configure Models button and info text
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Co-authored-by: dayuan.jiang <jdy.toh@gmail.com>
* enhancement: Add URL format hint to Base URL field (#593)
Add dynamic provider-specific format examples to Base URL field labels to clarify expected URL format. Includes missing defaultBaseUrl values for providers.
* fix: Use generic example URL instead of OpenAI URL for fallback
