refactor(settings): remove wrapper layers, dead props and unused dictionary keys

- components/model-selector.tsx uses Dialog, Command and Tooltip
  directly; delete components/ai-elements/model-selector.tsx and
  components/button-with-tooltip.tsx; one renderGroups for both lists;
  no "Server · " prefix round trip
- components/ui: drop CommandDialog, CommandShortcut and six unused
  shadcn exports
- model-config-dialog: no type-to-confirm on provider delete;
  provider-credentials-fields: drop footer and bedrockApiKey
- hooks/use-model-config.ts and lib/types/model-config.ts: remove the
  2025-12 single-provider migration, resetConfig, selectedModel and
  fields nothing reads
- components/chat/TemplateFormDialog.tsx replaces the create and edit
  dialogs; TemplatePanel drops the setInput fallback, the
  templatesChanged listener, dictionary fallbacks and formatLastUsed;
  lib/template-storage.ts drops getTemplate, clickCount and indexes
- reasoning.tsx becomes one component; shimmer uses a CSS keyframe
  (motion and @radix-ui/react-use-controllable-state removed)
- error-toast.tsx deleted in favour of toast.error; ValidationCard
  drops the idle status; dev-xml-simulator uses English literals
- admin: no enum setting type, shared types from lib/admin
  (AdminProviderInput stays exported for that), ENABLE_HISTORY_XML_REPLACE
  entry removed
- app/globals.css: drop check-pop, --ease-spring, --duration-normal
  and the shadow aliases
- dictionaries: 81 unused keys removed from all four languages

components/chat/ValidationCard.tsx

@@ -16,7 +16,6 @@ import { useDictionary } from "@/hooks/use-dictionary"
 import type { ValidationResult } from "@/lib/diagram-validator"
 
 export type ValidationStatus =
-    | "idle"
     | "capturing"
     | "validating"
     | "success"
@@ -159,13 +158,10 @@ export function ValidationCard({
                     color: "text-gray-600 bg-gray-50",
                     icon: <Check className="h-4 w-4" aria-hidden="true" />,
                 }
-            default:
-                return null
         }
     }
 
     const statusDisplay = getStatusDisplay()
-    if (!statusDisplay || state.status === "idle") return null
 
     return (
         <div className="my-3 rounded-xl border border-border/60 bg-muted/30 overflow-hidden">