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.

libs/model-resolver/README.md

@@ -30,15 +30,15 @@ const model2 = resolveModelString('haiku');
 // Returns: 'claude-haiku-4-5'
 
 const model3 = resolveModelString('opus');
-// Returns: 'claude-opus-4-5-20251101'
+// Returns: 'claude-opus-4-6'
 
 // Use with custom default
 const model4 = resolveModelString(undefined, 'claude-sonnet-4-20250514');
 // Returns: 'claude-sonnet-4-20250514' (default)
 
 // Direct model ID passthrough
-const model5 = resolveModelString('claude-opus-4-5-20251101');
-// Returns: 'claude-opus-4-5-20251101' (unchanged)
+const model5 = resolveModelString('claude-opus-4-6');
+// Returns: 'claude-opus-4-6' (unchanged)
 ```
 
 ### Get Effective Model
@@ -72,7 +72,7 @@ console.log(DEFAULT_MODELS.chat); // 'claude-sonnet-4-20250514'
 // Model alias mappings
 console.log(CLAUDE_MODEL_MAP.haiku); // 'claude-haiku-4-5'
 console.log(CLAUDE_MODEL_MAP.sonnet); // 'claude-sonnet-4-20250514'
-console.log(CLAUDE_MODEL_MAP.opus); // 'claude-opus-4-5-20251101'
+console.log(CLAUDE_MODEL_MAP.opus); // 'claude-opus-4-6'
 ```
 
 ## Usage Example
@@ -103,7 +103,7 @@ const feature: Feature = {
 };
 
 prepareFeatureExecution(feature);
-// Output: Executing feature with model: claude-opus-4-5-20251101
+// Output: Executing feature with model: claude-opus-4-6
 ```
 
 ## Supported Models
@@ -112,7 +112,7 @@ prepareFeatureExecution(feature);
 
 - `haiku` → `claude-haiku-4-5`
 - `sonnet` → `claude-sonnet-4-20250514`
-- `opus` → `claude-opus-4-5-20251101`
+- `opus` → `claude-opus-4-6`
 
 ### Model Selection Guide
 

libs/model-resolver/tests/resolver.test.ts

@@ -484,12 +484,12 @@ describe('model-resolver', () => {
 
       it('should handle full Claude model string in entry', () => {
         const entry: PhaseModelEntry = {
-          model: 'claude-opus-4-5-20251101',
+          model: 'claude-opus-4-6',
           thinkingLevel: 'high',
         };
         const result = resolvePhaseModel(entry);
 
-        expect(result.model).toBe('claude-opus-4-5-20251101');
+        expect(result.model).toBe('claude-opus-4-6');
         expect(result.thinkingLevel).toBe('high');
       });
     });

libs/types/src/index.ts

@@ -196,6 +196,8 @@ export {
   PROJECT_SETTINGS_VERSION,
   THINKING_TOKEN_BUDGET,
   getThinkingTokenBudget,
+  isAdaptiveThinkingModel,
+  getThinkingLevelsForModel,
   // Event hook constants
   EVENT_HOOK_TRIGGER_LABELS,
   // Claude-compatible provider templates (new)

libs/types/src/model-display.ts

@@ -149,6 +149,7 @@ export const THINKING_LEVELS: ThinkingLevelOption[] = [
   { id: 'medium', label: 'Medium' },
   { id: 'high', label: 'High' },
   { id: 'ultrathink', label: 'Ultrathink' },
+  { id: 'adaptive', label: 'Adaptive' },
 ];
 
 /**
@@ -162,6 +163,7 @@ export const THINKING_LEVEL_LABELS: Record<ThinkingLevel, string> = {
   medium: 'Med',
   high: 'High',
   ultrathink: 'Ultra',
+  adaptive: 'Adaptive',
 };
 
 /**

libs/types/src/model.ts

@@ -18,7 +18,7 @@ export type ClaudeCanonicalId = 'claude-haiku' | 'claude-sonnet' | 'claude-opus'
 export const CLAUDE_CANONICAL_MAP: Record<ClaudeCanonicalId, string> = {
   'claude-haiku': 'claude-haiku-4-5-20251001',
   'claude-sonnet': 'claude-sonnet-4-5-20250929',
-  'claude-opus': 'claude-opus-4-5-20251101',
+  'claude-opus': 'claude-opus-4-6',
 } as const;
 
 /**
@@ -29,7 +29,7 @@ export const CLAUDE_CANONICAL_MAP: Record<ClaudeCanonicalId, string> = {
 export const CLAUDE_MODEL_MAP: Record<string, string> = {
   haiku: 'claude-haiku-4-5-20251001',
   sonnet: 'claude-sonnet-4-5-20250929',
-  opus: 'claude-opus-4-5-20251101',
+  opus: 'claude-opus-4-6',
 } as const;
 
 /**
@@ -99,7 +99,7 @@ export function getAllCodexModelIds(): CodexModelId[] {
  * Uses canonical prefixed IDs for consistent routing.
  */
 export const DEFAULT_MODELS = {
-  claude: 'claude-opus-4-5-20251101',
+  claude: 'claude-opus-4-6',
   cursor: 'cursor-auto', // Cursor's recommended default (with prefix)
   codex: CODEX_MODEL_MAP.gpt52Codex, // GPT-5.2-Codex is the most advanced agentic coding model
 } as const;

libs/types/src/settings.ts

@@ -213,7 +213,7 @@ export type PlanningMode = 'skip' | 'lite' | 'spec' | 'full';
 export type ServerLogLevel = 'error' | 'warn' | 'info' | 'debug';
 
 /** ThinkingLevel - Extended thinking levels for Claude models (reasoning intensity) */
-export type ThinkingLevel = 'none' | 'low' | 'medium' | 'high' | 'ultrathink';
+export type ThinkingLevel = 'none' | 'low' | 'medium' | 'high' | 'ultrathink' | 'adaptive';
 
 /**
  * SidebarStyle - Sidebar layout style options
@@ -237,6 +237,7 @@ export const THINKING_TOKEN_BUDGET: Record<ThinkingLevel, number | undefined> =
   medium: 10000, // Light reasoning
   high: 16000, // Complex tasks (recommended starting point)
   ultrathink: 32000, // Maximum safe (above this risks timeouts)
+  adaptive: undefined, // Adaptive thinking (Opus 4.6) - SDK handles token allocation
 };
 
 /**
@@ -247,6 +248,26 @@ export function getThinkingTokenBudget(level: ThinkingLevel | undefined): number
   return THINKING_TOKEN_BUDGET[level];
 }
 
+/**
+ * Check if a model uses adaptive thinking (Opus 4.6+)
+ * Adaptive thinking models let the SDK decide token allocation automatically.
+ */
+export function isAdaptiveThinkingModel(model: string): boolean {
+  return model.includes('opus-4-6') || model === 'claude-opus';
+}
+
+/**
+ * Get the available thinking levels for a given model.
+ * - Opus 4.6: Only 'none' and 'adaptive' (SDK handles token allocation)
+ * - Others: Full range of manual thinking levels
+ */
+export function getThinkingLevelsForModel(model: string): ThinkingLevel[] {
+  if (isAdaptiveThinkingModel(model)) {
+    return ['none', 'adaptive'];
+  }
+  return ['none', 'low', 'medium', 'high', 'ultrathink'];
+}
+
 /** ModelProvider - AI model provider for credentials and API key management */
 export type ModelProvider = 'claude' | 'cursor' | 'codex' | 'opencode' | 'gemini' | 'copilot';