feat: add multi-provider model configuration

- Add model config dialog for managing multiple AI providers
- Support for OpenAI, Anthropic, Google, Azure, Bedrock, OpenRouter, DeepSeek, SiliconFlow, Ollama, and AI Gateway
- Add model selector dropdown in chat panel header
- Add API key validation endpoint
- Add custom model ID input with keyboard navigation
- Fix hover highlight in Command component
- Add suggested models for each provider including latest Claude 4.5 series
- Store configuration locally in browser

components/ai-elements/model-selector.tsx

@@ -0,0 +1,148 @@
+import type { ComponentProps, ReactNode } from "react"
+import {
+    Command,
+    CommandDialog,
+    CommandEmpty,
+    CommandGroup,
+    CommandInput,
+    CommandItem,
+    CommandList,
+    CommandSeparator,
+    CommandShortcut,
+} from "@/components/ui/command"
+import {
+    Dialog,
+    DialogContent,
+    DialogTitle,
+    DialogTrigger,
+} from "@/components/ui/dialog"
+import { cn } from "@/lib/utils"
+
+export type ModelSelectorProps = ComponentProps<typeof Dialog>
+
+export const ModelSelector = (props: ModelSelectorProps) => (
+    <Dialog {...props} />
+)
+
+export type ModelSelectorTriggerProps = ComponentProps<typeof DialogTrigger>
+
+export const ModelSelectorTrigger = (props: ModelSelectorTriggerProps) => (
+    <DialogTrigger {...props} />
+)
+
+export type ModelSelectorContentProps = ComponentProps<typeof DialogContent> & {
+    title?: ReactNode
+}
+
+export const ModelSelectorContent = ({
+    className,
+    children,
+    title = "Model Selector",
+    ...props
+}: ModelSelectorContentProps) => (
+    <DialogContent className={cn("p-0", className)} {...props}>
+        <DialogTitle className="sr-only">{title}</DialogTitle>
+        <Command className="**:data-[slot=command-input-wrapper]:h-auto">
+            {children}
+        </Command>
+    </DialogContent>
+)
+
+export type ModelSelectorDialogProps = ComponentProps<typeof CommandDialog>
+
+export const ModelSelectorDialog = (props: ModelSelectorDialogProps) => (
+    <CommandDialog {...props} />
+)
+
+export type ModelSelectorInputProps = ComponentProps<typeof CommandInput>
+
+export const ModelSelectorInput = ({
+    className,
+    ...props
+}: ModelSelectorInputProps) => (
+    <CommandInput className={cn("h-auto py-3.5", className)} {...props} />
+)
+
+export type ModelSelectorListProps = ComponentProps<typeof CommandList>
+
+export const ModelSelectorList = (props: ModelSelectorListProps) => (
+    <CommandList {...props} />
+)
+
+export type ModelSelectorEmptyProps = ComponentProps<typeof CommandEmpty>
+
+export const ModelSelectorEmpty = (props: ModelSelectorEmptyProps) => (
+    <CommandEmpty {...props} />
+)
+
+export type ModelSelectorGroupProps = ComponentProps<typeof CommandGroup>
+
+export const ModelSelectorGroup = (props: ModelSelectorGroupProps) => (
+    <CommandGroup {...props} />
+)
+
+export type ModelSelectorItemProps = ComponentProps<typeof CommandItem>
+
+export const ModelSelectorItem = (props: ModelSelectorItemProps) => (
+    <CommandItem {...props} />
+)
+
+export type ModelSelectorShortcutProps = ComponentProps<typeof CommandShortcut>
+
+export const ModelSelectorShortcut = (props: ModelSelectorShortcutProps) => (
+    <CommandShortcut {...props} />
+)
+
+export type ModelSelectorSeparatorProps = ComponentProps<
+    typeof CommandSeparator
+>
+
+export const ModelSelectorSeparator = (props: ModelSelectorSeparatorProps) => (
+    <CommandSeparator {...props} />
+)
+
+export type ModelSelectorLogoProps = Omit<
+    ComponentProps<"img">,
+    "src" | "alt"
+> & {
+    provider: string
+}
+
+export const ModelSelectorLogo = ({
+    provider,
+    className,
+    ...props
+}: ModelSelectorLogoProps) => (
+    <img
+        {...props}
+        alt={`${provider} logo`}
+        className={cn("size-4 dark:invert", className)}
+        height={16}
+        src={`https://models.dev/logos/${provider}.svg`}
+        width={16}
+    />
+)
+
+export type ModelSelectorLogoGroupProps = ComponentProps<"div">
+
+export const ModelSelectorLogoGroup = ({
+    className,
+    ...props
+}: ModelSelectorLogoGroupProps) => (
+    <div
+        className={cn(
+            "-space-x-1 flex shrink-0 items-center [&>img]:rounded-full [&>img]:bg-background [&>img]:p-px [&>img]:ring-1 dark:[&>img]:bg-foreground",
+            className,
+        )}
+        {...props}
+    />
+)
+
+export type ModelSelectorNameProps = ComponentProps<"span">
+
+export const ModelSelectorName = ({
+    className,
+    ...props
+}: ModelSelectorNameProps) => (
+    <span className={cn("flex-1 truncate text-left", className)} {...props} />
+)