feat: add Claude Code provider support

Implements Claude Code as a new AI provider that uses the Claude Code CLI
without requiring API keys. This enables users to leverage Claude models
through their local Claude Code installation.

Key changes:
- Add complete AI SDK v1 implementation for Claude Code provider
  - Custom SDK with streaming/non-streaming support
  - Session management for conversation continuity
  - JSON extraction for object generation mode
  - Support for advanced settings (maxTurns, allowedTools, etc.)

- Integrate Claude Code into Task Master's provider system
  - Update ai-services-unified.js to handle keyless authentication
  - Add provider to supported-models.json with opus/sonnet models
  - Ensure correct maxTokens values are applied (opus: 32000, sonnet: 64000)

- Fix maxTokens configuration issue
  - Add max_tokens property to getAvailableModels() output
  - Update setModel() to properly handle claude-code models
  - Create update-config-tokens.js utility for init process

- Add comprehensive documentation
  - User guide with configuration examples
  - Advanced settings explanation and future integration options

The implementation maintains full backward compatibility with existing
providers while adding seamless Claude Code support to all Task Master
commands.

scripts/init.js

@@ -30,6 +30,7 @@ import {
 	convertAllRulesToProfileRules,
 	getRulesProfile
 } from '../src/utils/rule-transformer.js';
+import { updateConfigMaxTokens } from './modules/update-config-tokens.js';
 
 import { execSync } from 'child_process';
 import {
@@ -622,6 +623,14 @@ function createProjectStructure(
 			...replacements
 		}
 	);
+	
+	// Update config.json with correct maxTokens values from supported-models.json
+	const configPath = path.join(targetDir, TASKMASTER_CONFIG_FILE);
+	if (updateConfigMaxTokens(configPath)) {
+		log('info', 'Updated config with correct maxTokens values');
+	} else {
+		log('warn', 'Could not update maxTokens in config');
+	}
 
 	// Copy .gitignore with GitTasks preference
 	try {

scripts/modules/update-config-tokens.js

@@ -0,0 +1,53 @@
+/**
+ * update-config-tokens.js
+ * Updates config.json with correct maxTokens values from supported-models.json
+ */
+
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+import { dirname } from 'path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+/**
+ * Updates the config file with correct maxTokens values from supported-models.json
+ * @param {string} configPath - Path to the config.json file to update
+ * @returns {boolean} True if successful, false otherwise
+ */
+export function updateConfigMaxTokens(configPath) {
+	try {
+		// Load supported models
+		const supportedModelsPath = path.join(__dirname, 'supported-models.json');
+		const supportedModels = JSON.parse(fs.readFileSync(supportedModelsPath, 'utf-8'));
+		
+		// Load config
+		const config = JSON.parse(fs.readFileSync(configPath, 'utf-8'));
+		
+		// Update each role's maxTokens if the model exists in supported-models.json
+		const roles = ['main', 'research', 'fallback'];
+		
+		for (const role of roles) {
+			if (config.models && config.models[role]) {
+				const provider = config.models[role].provider;
+				const modelId = config.models[role].modelId;
+				
+				// Find the model in supported models
+				if (supportedModels[provider]) {
+					const modelData = supportedModels[provider].find(m => m.id === modelId);
+					if (modelData && modelData.max_tokens) {
+						config.models[role].maxTokens = modelData.max_tokens;
+					}
+				}
+			}
+		}
+		
+		// Write back the updated config
+		fs.writeFileSync(configPath, JSON.stringify(config, null, 2));
+		return true;
+	} catch (error) {
+		console.error('Error updating config maxTokens:', error.message);
+		return false;
+	}
+}