feat: update Claude model to Opus 4.6 and enhance adaptive thinking support

- Changed model identifier from `claude-opus-4-5-20251101` to `claude-opus-4-6` across various files, including documentation and code references.
- Updated the SDK to support adaptive thinking for Opus 4.6, allowing the model to determine its own reasoning depth.
- Enhanced the thinking level options to include 'adaptive' and adjusted related components to reflect this change.
- Updated tests to ensure compatibility with the new model and its features.

These changes improve the model's capabilities and user experience by leveraging adaptive reasoning.

apps/server/src/lib/sdk-options.ts

@@ -253,11 +253,27 @@ function buildMcpOptions(config: CreateSdkOptionsConfig): McpOptions {
 /**
  * Build thinking options for SDK configuration.
  * Converts ThinkingLevel to maxThinkingTokens for the Claude SDK.
+ * For adaptive thinking (Opus 4.6), omits maxThinkingTokens to let the model
+ * decide its own reasoning depth.
  *
  * @param thinkingLevel - The thinking level to convert
- * @returns Object with maxThinkingTokens if thinking is enabled
+ * @returns Object with maxThinkingTokens if thinking is enabled with a budget
  */
 function buildThinkingOptions(thinkingLevel?: ThinkingLevel): Partial<Options> {
+  if (!thinkingLevel || thinkingLevel === 'none') {
+    return {};
+  }
+
+  // Adaptive thinking (Opus 4.6): don't set maxThinkingTokens
+  // The model will use adaptive thinking by default
+  if (thinkingLevel === 'adaptive') {
+    logger.debug(
+      `buildThinkingOptions: thinkingLevel="adaptive" -> no maxThinkingTokens (model decides)`
+    );
+    return {};
+  }
+
+  // Manual budget-based thinking for Haiku/Sonnet
   const maxThinkingTokens = getThinkingTokenBudget(thinkingLevel);
   logger.debug(
     `buildThinkingOptions: thinkingLevel="${thinkingLevel}" -> maxThinkingTokens=${maxThinkingTokens}`

apps/server/src/providers/claude-provider.ts

@@ -219,8 +219,11 @@ export class ClaudeProvider extends BaseProvider {
     // claudeCompatibleProvider takes precedence over claudeApiProfile
     const providerConfig = claudeCompatibleProvider || claudeApiProfile;
 
-    // Convert thinking level to token budget
-    const maxThinkingTokens = getThinkingTokenBudget(thinkingLevel);
+    // Build thinking configuration
+    // Adaptive thinking (Opus 4.6): don't set maxThinkingTokens, model uses adaptive by default
+    // Manual thinking (Haiku/Sonnet): use budget_tokens
+    const maxThinkingTokens =
+      thinkingLevel === 'adaptive' ? undefined : getThinkingTokenBudget(thinkingLevel);
 
     // Build Claude SDK options
     const sdkOptions: Options = {
@@ -349,13 +352,13 @@ export class ClaudeProvider extends BaseProvider {
   getAvailableModels(): ModelDefinition[] {
     const models = [
       {
-        id: 'claude-opus-4-5-20251101',
-        name: 'Claude Opus 4.5',
-        modelString: 'claude-opus-4-5-20251101',
+        id: 'claude-opus-4-6',
+        name: 'Claude Opus 4.6',
+        modelString: 'claude-opus-4-6',
         provider: 'anthropic',
-        description: 'Most capable Claude model',
+        description: 'Most capable Claude model with adaptive thinking',
         contextWindow: 200000,
-        maxOutputTokens: 16000,
+        maxOutputTokens: 128000,
         supportsVision: true,
         supportsTools: true,
         tier: 'premium' as const,

apps/server/src/providers/provider-factory.ts

@@ -103,7 +103,7 @@ export class ProviderFactory {
   /**
    * Get the appropriate provider for a given model ID
    *
-   * @param modelId Model identifier (e.g., "claude-opus-4-5-20251101", "cursor-gpt-4o", "cursor-auto")
+   * @param modelId Model identifier (e.g., "claude-opus-4-6", "cursor-gpt-4o", "cursor-auto")
    * @param options Optional settings
    * @param options.throwOnDisconnected Throw error if provider is disconnected (default: true)
    * @returns Provider instance for the model