feat: harden support, localize knowledge and add operator availability [skip ci]

Source-only publication of reviewed commit 64e96a7f423673dc29ad56485be9fc79bce8af1c.

Passed in isolation: focused frontend/backend tests, race checks, TypeScript typecheck, lint, Go compilation, Flowgram build, and deterministic SDK build/tests.

Not accepted as a production release: Next.js export/native assembly remains blocked by environment memory limits; browser interaction and MySQL staging acceptance remain unverified. No production server, database/schema, runtime configuration, deployment, release tag, or workflow execution was performed.

Expected source tree: 0a4a7528e9.

web/components/option-combobox.tsx

@@ -1,3 +1,4 @@
+// Modified in this independent fork for support availability; see docs/hardening/README.md.
 "use client"
 
 import { useState, type ReactNode } from "react"
@@ -31,6 +32,7 @@ export type ComboboxOption = {
 }
 
 type CommonOptionComboboxProps = {
+  ariaLabel?: string
   options: ComboboxOption[]
   placeholder: string
   searchPlaceholder?: string
@@ -62,6 +64,7 @@ type OptionComboboxProps = CommonOptionComboboxProps &
 export function OptionCombobox(props: OptionComboboxProps) {
   const {
     options,
+    ariaLabel,
     placeholder,
     searchPlaceholder,
     emptyText,
@@ -114,6 +117,7 @@ export function OptionCombobox(props: OptionComboboxProps) {
           <Button
             variant="outline"
             role="combobox"
+            aria-label={ariaLabel}
             className={cn("m-0 w-full justify-between font-normal", triggerClassName)}
             disabled={disabled}
           />