Simplify auth, remove abstraction layers, add shadcn components

- Delete lib/api/errors.ts and lib/api/auth-guard.ts, inline
  NextResponse.json() error responses directly in route handlers
- Replace non-standard amber CSS variables with primary/primary-foreground
- Regenerate shadcn UI components with biome-ignore comments
- Add CLAUDE.md for repository guidance
- Update dependencies and pnpm lockfile

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

components/ui/select.tsx

@@ -16,7 +16,7 @@ function SelectGroup({ className, ...props }: SelectPrimitive.Group.Props) {
   return (
     <SelectPrimitive.Group
       data-slot="select-group"
-      className={cn("scroll-my-1", className)}
+      className={cn("scroll-my-1 p-1", className)}
       {...props}
     />
   );
@@ -45,7 +45,7 @@ function SelectTrigger({
       data-slot="select-trigger"
       data-size={size}
       className={cn(
-        "border-input data-placeholder:text-muted-foreground dark:bg-input/30 dark:hover:bg-input/50 focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive dark:aria-invalid:border-destructive/50 flex w-fit items-center justify-between gap-1.5 rounded-none border bg-transparent py-2 pr-2 pl-2.5 text-xs whitespace-nowrap transition-colors outline-none select-none focus-visible:ring-1 disabled:cursor-not-allowed disabled:opacity-50 aria-invalid:ring-1 data-[size=default]:h-8 data-[size=sm]:h-7 data-[size=sm]:rounded-none *:data-[slot=select-value]:line-clamp-1 *:data-[slot=select-value]:flex *:data-[slot=select-value]:items-center *:data-[slot=select-value]:gap-1.5 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4",
+        "border-input data-placeholder:text-muted-foreground bg-input/20 dark:bg-input/30 dark:hover:bg-input/50 focus-visible:border-ring focus-visible:ring-ring/30 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive dark:aria-invalid:border-destructive/50 flex w-fit items-center justify-between gap-1.5 rounded-md border px-2 py-1.5 text-xs/relaxed whitespace-nowrap transition-colors outline-none focus-visible:ring-2 disabled:cursor-not-allowed disabled:opacity-50 aria-invalid:ring-2 data-[size=default]:h-7 data-[size=sm]:h-6 *:data-[slot=select-value]:line-clamp-1 *:data-[slot=select-value]:flex *:data-[slot=select-value]:items-center *:data-[slot=select-value]:gap-1.5 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-3.5",
         className,
       )}
       {...props}
@@ -53,7 +53,7 @@ function SelectTrigger({
       {children}
       <SelectPrimitive.Icon
         render={
-          <IconSelector className="text-muted-foreground pointer-events-none size-4" />
+          <IconSelector className="text-muted-foreground pointer-events-none size-3.5" />
         }
       />
     </SelectPrimitive.Trigger>
@@ -88,7 +88,7 @@ function SelectContent({
           data-slot="select-content"
           data-align-trigger={alignItemWithTrigger}
           className={cn(
-            "bg-popover text-popover-foreground data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 ring-foreground/10 data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2 relative isolate z-50 max-h-(--available-height) w-(--anchor-width) min-w-36 origin-(--transform-origin) overflow-x-hidden overflow-y-auto rounded-none shadow-md ring-1 duration-100 data-[align-trigger=true]:animate-none",
+            "bg-popover text-popover-foreground data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 ring-foreground/10 data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2 relative isolate z-50 max-h-(--available-height) w-(--anchor-width) min-w-32 origin-(--transform-origin) overflow-x-hidden overflow-y-auto rounded-lg shadow-md ring-1 duration-100 data-[align-trigger=true]:animate-none",
             className,
           )}
           {...props}
@@ -109,7 +109,7 @@ function SelectLabel({
   return (
     <SelectPrimitive.GroupLabel
       data-slot="select-label"
-      className={cn("text-muted-foreground px-2 py-2 text-xs", className)}
+      className={cn("text-muted-foreground px-2 py-1.5 text-xs", className)}
       {...props}
     />
   );
@@ -124,7 +124,7 @@ function SelectItem({
     <SelectPrimitive.Item
       data-slot="select-item"
       className={cn(
-        "focus:bg-accent focus:text-accent-foreground not-data-[variant=destructive]:focus:**:text-accent-foreground relative flex w-full cursor-default items-center gap-2 rounded-none py-2 pr-8 pl-2 text-xs outline-hidden select-none data-disabled:pointer-events-none data-disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4 *:[span]:last:flex *:[span]:last:items-center *:[span]:last:gap-2",
+        "focus:bg-accent focus:text-accent-foreground not-data-[variant=destructive]:focus:**:text-accent-foreground relative flex min-h-7 w-full cursor-default items-center gap-2 rounded-md px-2 py-1 text-xs/relaxed outline-hidden select-none data-disabled:pointer-events-none data-disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-3.5 *:[span]:last:flex *:[span]:last:items-center *:[span]:last:gap-2",
         className,
       )}
       {...props}
@@ -134,7 +134,7 @@ function SelectItem({
       </SelectPrimitive.ItemText>
       <SelectPrimitive.ItemIndicator
         render={
-          <span className="pointer-events-none absolute right-2 flex size-4 items-center justify-center" />
+          <span className="pointer-events-none absolute right-2 flex items-center justify-center" />
         }
       >
         <IconCheck className="pointer-events-none" />
@@ -150,7 +150,10 @@ function SelectSeparator({
   return (
     <SelectPrimitive.Separator
       data-slot="select-separator"
-      className={cn("bg-border pointer-events-none -mx-1 h-px", className)}
+      className={cn(
+        "bg-border/50 pointer-events-none -mx-1 my-1 h-px",
+        className,
+      )}
       {...props}
     />
   );
@@ -164,7 +167,7 @@ function SelectScrollUpButton({
     <SelectPrimitive.ScrollUpArrow
       data-slot="select-scroll-up-button"
       className={cn(
-        "bg-popover top-0 z-10 flex w-full cursor-default items-center justify-center py-1 [&_svg:not([class*='size-'])]:size-4",
+        "bg-popover top-0 z-10 flex w-full cursor-default items-center justify-center py-1 [&_svg:not([class*='size-'])]:size-3.5",
         className,
       )}
       {...props}
@@ -182,7 +185,7 @@ function SelectScrollDownButton({
     <SelectPrimitive.ScrollDownArrow
       data-slot="select-scroll-down-button"
       className={cn(
-        "bg-popover bottom-0 z-10 flex w-full cursor-default items-center justify-center py-1 [&_svg:not([class*='size-'])]:size-4",
+        "bg-popover bottom-0 z-10 flex w-full cursor-default items-center justify-center py-1 [&_svg:not([class*='size-'])]:size-3.5",
         className,
       )}
       {...props}