Replace claude-sonnet-4-6 with claude-sonnet-5 (#151)

Sonnet 5 supersedes Sonnet 4.6 at the same standard pricing ($3/$15
per MTok), so this is a straight model swap: new ChatModel id, env var
(AZURE_ANTHROPIC_SONNET5_DEPLOYMENT_NAME), and display name.

Author: saoc90

src/.env.example

@@ -49,7 +49,7 @@ DOWNGRADE_INTENT_DEFAULT_MODEL=
 AZURE_ANTHROPIC_RESOURCE_NAME=
 AZURE_ANTHROPIC_API_KEY=
 AZURE_ANTHROPIC_OPUS48_DEPLOYMENT_NAME=claude-opus-4-8
-AZURE_ANTHROPIC_SONNET46_DEPLOYMENT_NAME=claude-sonnet-4-6-2
+AZURE_ANTHROPIC_SONNET5_DEPLOYMENT_NAME=claude-sonnet-5
 
 # DALL-E image creation endpoint config
 AZURE_OPENAI_DALLE_API_KEY=222222

src/features/chat-page/chat-services/models.ts

@@ -26,7 +26,7 @@ export type ChatModel =
   // Anthropic Claude models served via the Azure /anthropic surface
   // (Messages API) through the "anthropic" provider seam.
   | "claude-opus-4-8"
-  | "claude-sonnet-4-6-2";
+  | "claude-sonnet-5";
 
 export interface ModelPricing {
   inputPerMillion: number;
@@ -236,9 +236,9 @@ export const MODEL_CONFIGS: Record<ChatModel, ModelConfig> = {
     // API). Can't call the Azure built-ins (image gen etc.).
     capabilities: ["vision", "webSearch"],
   },
-  "claude-sonnet-4-6-2": {
-    id: "claude-sonnet-4-6-2",
-    name: "Claude Sonnet 4.6",
+  "claude-sonnet-5": {
+    id: "claude-sonnet-5",
+    name: "Claude Sonnet 5",
     description: "Balanced Anthropic model — fast, strong general performance",
     getInstance: () => {
       throw new Error(
@@ -248,7 +248,7 @@ export const MODEL_CONFIGS: Record<ChatModel, ModelConfig> = {
     provider: "anthropic",
     supportsReasoning: true,
     supportsResponsesAPI: false,
-    deploymentName: process.env.AZURE_ANTHROPIC_SONNET46_DEPLOYMENT_NAME,
+    deploymentName: process.env.AZURE_ANTHROPIC_SONNET5_DEPLOYMENT_NAME,
     pricing: { inputPerMillion: 3.0, outputPerMillion: 15.0, cachedInputPerMillion: 0.3 },
     contextWindow: 1000000,
     // Image input + native web search/fetch (wired in the anthropic seam).

src/features/chat-page/chat-services/models/__tests__/provider.test.ts

@@ -94,7 +94,7 @@ describe("resolveAnthropicModel — DI seam", () => {
   });
 
   it("throws when no deploymentName is configured for the Anthropic model", () => {
-    const modelId: ChatModel = "claude-sonnet-4-6-2";
+    const modelId: ChatModel = "claude-sonnet-5";
     (MODEL_CONFIGS[modelId] as any).deploymentName = undefined;
 
     expect(() => resolveAnthropicModel(modelId)).toThrow(/no deploymentName/);

src/features/chat-page/chat-services/models/provider-seam.test.ts

@@ -247,7 +247,7 @@ describe("provider-seam — Anthropic branch", () => {
 
   it("enables adaptive thinking + mapped effort; no Azure-Responses keys; no tools when toggles off", () => {
     const r = resolveProvider({
-      modelId: "claude-sonnet-4-6-2",
+      modelId: "claude-sonnet-5",
       thread: { id: "thread-xyz", codeInterpreterContainerId: undefined },
       toggles: offToggles,
       reasoning: { supported: true, effort: "high" },