fix(docs): a11y projectconfigvariables (#50002)

## What kind of change does this PR introduce?

bug fix for accessibility, fixes
[docs-1280](https://linear.app/supabase/issue/DOCS-1280/projectconfigvariables-label-the-readonly-inputs-and-name)

## What is the current behavior?

the project url and api key fields in `ProjectConfigVariables` have no
associated label, so a screen reader announces an edit field with no
indication of which value it holds

## What is the new behavior?

- associates a `<label>` with each readonly input, so the fields
announce as "project url" and "publishable key"
- names each copy button after the value it copies
- drops `role="combobox"` from the trigger, keeping the `aria-haspopup`,
`aria-expanded` and `aria-controls` radix already supplies
- names the trigger from its content instead of `aria-label`, so it
announces the current selection
- names the shared `CommandInput` reset button and hides its icons

## test

- `pnpm dev:docs`
- `/docs/guides/getting-started/quickstarts/nextjs` (`url` +
`publishable`)
- `/docs/guides/auth/server-side/creating-a-client`, branch selector,
needs a branching-enabled project
- `/docs/guides/observability/log-drains`
- `api_settings` in any getting-started quickstart

## Additional context

reverses part of #49952 as that pr added `aria-label` to satisfy
`button-name`, but did replace the accessible name rather than adding to
it _ the sr-only prefix added here keeps the rule passing and announces
the selection

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Accessibility**
* Improved screen reader support for variable configuration controls,
including clearer labels and copy-status announcements.
* Enhanced combobox and search interactions with accessible labeling,
empty-result announcements, and clearer reset-button names.
* Decorative icons and visual-only messages are now hidden from
assistive technologies.
* **Tests**
* Added accessibility coverage for search input icons and the
clear-search control.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

apps/docs/components/ProjectConfigVariables/ProjectConfigVariables.ComboBox.tsx

@@ -83,10 +83,8 @@ export function ComboBox<Opt extends ComboBoxOption>({
       <PopoverTrigger asChild>
         <Button
           variant="outline"
-          role="combobox"
           disabled={disabled}
           aria-expanded={open}
-          aria-label={`Select your ${name}`}
           className={cn(
             'overflow-hidden',
             'h-auto min-h-10',
@@ -96,17 +94,18 @@ export function ComboBox<Opt extends ComboBoxOption>({
             className
           )}
         >
+          <span className="sr-only">{name}: </span>
           {selectedDisplayName ??
             (isLoading && options.length > 0
               ? 'Loading...'
               : options.length === 0
                 ? `No ${name} found`
                 : `Select a ${name}...`)}
-          <ChevronsUpDown className="ml-2 h-4 w-4 shrink-0 opacity-50" />
+          <ChevronsUpDown className="ml-2 h-4 w-4 shrink-0 opacity-50" aria-hidden />
         </Button>
       </PopoverTrigger>
       <PopoverContent className="p-0" side="bottom" align="start">
-        <Command shouldFilter={useCommandSearch}>
+        <Command shouldFilter={useCommandSearch} label={`Search ${name}`}>
           <CommandInput
             placeholder={`Search ${name}...`}
             className="border-none ring-0"
@@ -115,7 +114,10 @@ export function ComboBox<Opt extends ComboBoxOption>({
             onValueChange={setSearch}
             handleReset={() => setSearch('')}
           />
-          <CommandList>
+          <span className="sr-only" role="status">
+            {!isLoading && search.length > 0 && options.length === 0 ? `No ${name} found` : ''}
+          </span>
+          <CommandList label={`${name} options`}>
             <CommandGroup>
               {isLoading ? (
                 <div className="px-2 py-1 flex flex-col gap-2">
@@ -125,7 +127,7 @@ export function ComboBox<Opt extends ComboBoxOption>({
               ) : (
                 <>
                   {search.length > 0 && options.length === 0 && (
-                    <p className="text-xs text-center text-foreground-lighter py-3">
+                    <p className="text-xs text-center text-foreground-lighter py-3" aria-hidden>
                       No {name}s found based on your search
                     </p>
                   )}
@@ -146,6 +148,7 @@ export function ComboBox<Opt extends ComboBoxOption>({
                             'mr-2 h-4 w-4',
                             selectedOption === option.value ? 'opacity-100' : 'opacity-0'
                           )}
+                          aria-hidden
                         />
                         {option.displayName}
                       </CommandItem>

apps/docs/components/ProjectConfigVariables/ProjectConfigVariables.tsx

@@ -34,7 +34,7 @@ import { useOnLogout } from '~/lib/userAuth'
 import { LOCAL_STORAGE_KEYS, useIsLoggedIn, useIsUserLoading } from 'common'
 import { Check, Copy } from 'lucide-react'
 import Link from 'next/link'
-import { useEffect, useMemo, useState } from 'react'
+import { useEffect, useId, useMemo, useState } from 'react'
 import CopyToClipboard from 'react-copy-to-clipboard'
 import { withErrorBoundary } from 'react-error-boundary'
 import { Button_Shadcn_ as Button, cn, Input } from 'ui'
@@ -303,7 +303,15 @@ function BranchSelector() {
   ) : null
 }
 
-function VariableView({ variable, className }: { variable: Variable; className?: string }) {
+function VariableView({
+  variable,
+  inputId,
+  className,
+}: {
+  variable: Variable
+  inputId: string
+  className?: string
+}) {
   const isUserLoading = useIsUserLoading()
   const isLoggedIn = useIsLoggedIn()
 
@@ -397,6 +405,7 @@ function VariableView({ variable, className }: { variable: Variable; className?:
       <div className={cn('flex items-center gap-2', className)}>
         <Input
           readOnly
+          id={inputId}
           type="text"
           className="font-mono"
           value={
@@ -422,11 +431,14 @@ function VariableView({ variable, className }: { variable: Variable; className?:
                 properties: { variable },
               })
             }}
-            aria-label="Copy"
+            aria-label={`Copy ${prettyFormatVariable[variable]}`}
           >
-            {copied ? <Check size="18" /> : <Copy size="18" />}
+            {copied ? <Check size="18" aria-hidden /> : <Copy size="18" aria-hidden />}
           </Button>
         </CopyToClipboard>
+        <span className="sr-only" role="status">
+          {copied ? `${prettyFormatVariable[variable]} copied` : ''}
+        </span>
       </div>
       {stateSummary === 'loggedIn.selectedProject.dataError' && (
         <p className="text-foreground-muted text-sm mt-2 mb-0 ml-1">
@@ -472,16 +484,21 @@ function ProjectConfigVariablesInternal({ variable }: { variable: Variable }) {
   const { clear: clearSharedStoreData } = useSnapshot(projectsStore)
   useOnLogout(clearSharedStoreData)
 
+  const inputId = useId()
+
   return (
     <div className="max-w-[min(100%, 500px)] my-6">
-      <span className={cn('block mt-0 mb-1 font-heading font-semibold', 'text-foreground')}>
+      <label
+        htmlFor={inputId}
+        className={cn('block mt-0 mb-1 font-heading font-semibold', 'text-foreground')}
+      >
         {prettyFormatVariable[variable]}
-      </span>
+      </label>
       <div className="flex flex-wrap gap-x-6">
         <OrgProjectSelector />
         <BranchSelector />
       </div>
-      <VariableView variable={variable} className="mt-1" />
+      <VariableView variable={variable} inputId={inputId} className="mt-1" />
       <LoginHint variable={variable} />
     </div>
   )

packages/ui/src/components/shadcn/ui/command.tsx

@@ -58,7 +58,7 @@ const CommandInput = React.forwardRef<
     ref
   ) => (
     <div className={cn('flex items-center border-b px-4', wrapperClassName)} cmdk-input-wrapper="">
-      {showSearchIcon && <Search className="h-4 w-4 shrink-0 opacity-50" />}
+      {showSearchIcon && <Search className="h-4 w-4 shrink-0 opacity-50" aria-hidden />}
       <CommandPrimitive.Input
         ref={ref}
         className={cn(
@@ -73,12 +73,13 @@ const CommandInput = React.forwardRef<
           tabIndex={props.disabled || !props.value?.length ? -1 : 0}
           disabled={props.disabled || !props.value?.length}
           onClick={handleReset}
+          aria-label="Clear search"
           className={cn(
             'text-foreground-lighter hover:text-foreground-light hover:cursor-pointer transition-all opacity-0 duration-100',
             !!props.value?.length && 'opacity-100'
           )}
         >
-          <RemoveIcon size={14} />
+          <RemoveIcon size={14} aria-hidden />
         </button>
       )}
     </div>