feat(catalog): add Claude Opus 4.8 to Anthropic model registry

Register `claude-opus-4-8` in the cliproxy model catalog, web-server
pricing table, and UI catalog as an additive entry next to 4.7. Defaults
are unchanged (claude provider stays on sonnet-4-6); users opt into 4.8
explicitly via ANTHROPIC_MODEL or the dashboard.

Configuration mirrors 4.7:
- adaptive thinking levels (low through max), max distinct from xhigh
- extendedContext (1M) available
- nativeImageInput
- pricing $5/$25 in/out, $6.25/$0.5 cache

Built [OnSteroids](https://onsteroids.ai)

ui/src/lib/model-catalogs.ts

@@ -630,10 +630,22 @@ export const MODEL_CATALOGS: Record<string, ProviderCatalog> = {
     displayName: 'Claude (Anthropic)',
     defaultModel: 'claude-sonnet-4-6',
     models: [
+      {
+        id: 'claude-opus-4-8',
+        name: 'Claude Opus 4.8',
+        description: 'Latest flagship model',
+        extendedContext: true,
+        presetMapping: {
+          default: 'claude-opus-4-8',
+          opus: 'claude-opus-4-8',
+          sonnet: 'claude-sonnet-4-6',
+          haiku: 'claude-haiku-4-5-20251001',
+        },
+      },
       {
         id: 'claude-opus-4-7',
         name: 'Claude Opus 4.7',
-        description: 'Latest flagship model',
+        description: 'Previous flagship model',
         extendedContext: true,
         presetMapping: {
           default: 'claude-opus-4-7',
@@ -645,7 +657,7 @@ export const MODEL_CATALOGS: Record<string, ProviderCatalog> = {
       {
         id: 'claude-opus-4-6',
         name: 'Claude Opus 4.6',
-        description: 'Previous flagship model',
+        description: 'Older flagship model',
         extendedContext: true,
         presetMapping: {
           default: 'claude-opus-4-6',

ui/tests/unit/ui/lib/preset-utils.test.ts

@@ -16,12 +16,14 @@ describe('claude preset utils', () => {
     vi.restoreAllMocks();
   });
 
-  it('keeps the claude catalog default on Sonnet 4.6 while exposing Opus 4.7', () => {
+  it('keeps the claude catalog default on Sonnet 4.6 while exposing Opus 4.7 and 4.8', () => {
     const claudeCatalog = MODEL_CATALOGS.claude;
+    const ids = claudeCatalog.models.map((model) => model.id);
 
     expect(claudeCatalog.defaultModel).toBe('claude-sonnet-4-6');
-    expect(claudeCatalog.models.map((model) => model.id)).toContain('claude-opus-4-7');
-    expect(claudeCatalog.models.map((model) => model.id)).toContain('claude-sonnet-4-6');
+    expect(ids).toContain('claude-opus-4-8');
+    expect(ids).toContain('claude-opus-4-7');
+    expect(ids).toContain('claude-sonnet-4-6');
   });
 
   it('applies the default claude preset from the catalog default model mapping', async () => {