refactor(config): Standardize env var access and config getters

This commit focuses on standardizing configuration and API key access patterns across key modules as part of subtask 61.34.

Key changes include:

- Refactored `ai-services.js` to remove global AI clients and use `resolveEnvVariable` for API key checks. Client instantiation now relies on `getAnthropicClient`/`getPerplexityClient` accepting a session object.

- Refactored `task-manager.js` (`analyzeTaskComplexity` function) to use the unified `generateTextService` from `ai-services-unified.js`, removing direct AI client calls.

- Replaced direct `process.env` access for model parameters and other configurations (`PERPLEXITY_MODEL`, `CONFIG.*`) in `task-manager.js` with calls to the appropriate getters from `config-manager.js` (e.g., `getResearchModelId(session)`, `getMainMaxTokens(session)`).

- Ensured `utils.js` (`resolveEnvVariable`) correctly handles potentially undefined session objects.

- Updated function signatures where necessary to propagate the `session` object for correct context-aware configuration/key retrieval.

This moves towards the goal of using `ai-client-factory.js` and `ai-services-unified.js` as the standard pattern for AI interactions and centralizing configuration management through `config-manager.js`.

scripts/modules/task-manager/remove-subtask.js

@@ -0,0 +1,119 @@
+import path from 'path';
+import { log, readJSON, writeJSON } from '../utils.js';
+import generateTaskFiles from './generate-task-files.js';
+
+/**
+ * Remove a subtask from its parent task
+ * @param {string} tasksPath - Path to the tasks.json file
+ * @param {string} subtaskId - ID of the subtask to remove in format "parentId.subtaskId"
+ * @param {boolean} convertToTask - Whether to convert the subtask to a standalone task
+ * @param {boolean} generateFiles - Whether to regenerate task files after removing the subtask
+ * @returns {Object|null} The removed subtask if convertToTask is true, otherwise null
+ */
+async function removeSubtask(
+	tasksPath,
+	subtaskId,
+	convertToTask = false,
+	generateFiles = true
+) {
+	try {
+		log('info', `Removing subtask ${subtaskId}...`);
+
+		// Read the existing tasks
+		const data = readJSON(tasksPath);
+		if (!data || !data.tasks) {
+			throw new Error(`Invalid or missing tasks file at ${tasksPath}`);
+		}
+
+		// Parse the subtask ID (format: "parentId.subtaskId")
+		if (!subtaskId.includes('.')) {
+			throw new Error(
+				`Invalid subtask ID format: ${subtaskId}. Expected format: "parentId.subtaskId"`
+			);
+		}
+
+		const [parentIdStr, subtaskIdStr] = subtaskId.split('.');
+		const parentId = parseInt(parentIdStr, 10);
+		const subtaskIdNum = parseInt(subtaskIdStr, 10);
+
+		// Find the parent task
+		const parentTask = data.tasks.find((t) => t.id === parentId);
+		if (!parentTask) {
+			throw new Error(`Parent task with ID ${parentId} not found`);
+		}
+
+		// Check if parent has subtasks
+		if (!parentTask.subtasks || parentTask.subtasks.length === 0) {
+			throw new Error(`Parent task ${parentId} has no subtasks`);
+		}
+
+		// Find the subtask to remove
+		const subtaskIndex = parentTask.subtasks.findIndex(
+			(st) => st.id === subtaskIdNum
+		);
+		if (subtaskIndex === -1) {
+			throw new Error(`Subtask ${subtaskId} not found`);
+		}
+
+		// Get a copy of the subtask before removing it
+		const removedSubtask = { ...parentTask.subtasks[subtaskIndex] };
+
+		// Remove the subtask from the parent
+		parentTask.subtasks.splice(subtaskIndex, 1);
+
+		// If parent has no more subtasks, remove the subtasks array
+		if (parentTask.subtasks.length === 0) {
+			delete parentTask.subtasks;
+		}
+
+		let convertedTask = null;
+
+		// Convert the subtask to a standalone task if requested
+		if (convertToTask) {
+			log('info', `Converting subtask ${subtaskId} to a standalone task...`);
+
+			// Find the highest task ID to determine the next ID
+			const highestId = Math.max(...data.tasks.map((t) => t.id));
+			const newTaskId = highestId + 1;
+
+			// Create the new task from the subtask
+			convertedTask = {
+				id: newTaskId,
+				title: removedSubtask.title,
+				description: removedSubtask.description || '',
+				details: removedSubtask.details || '',
+				status: removedSubtask.status || 'pending',
+				dependencies: removedSubtask.dependencies || [],
+				priority: parentTask.priority || 'medium' // Inherit priority from parent
+			};
+
+			// Add the parent task as a dependency if not already present
+			if (!convertedTask.dependencies.includes(parentId)) {
+				convertedTask.dependencies.push(parentId);
+			}
+
+			// Add the converted task to the tasks array
+			data.tasks.push(convertedTask);
+
+			log('info', `Created new task ${newTaskId} from subtask ${subtaskId}`);
+		} else {
+			log('info', `Subtask ${subtaskId} deleted`);
+		}
+
+		// Write the updated tasks back to the file
+		writeJSON(tasksPath, data);
+
+		// Generate task files if requested
+		if (generateFiles) {
+			log('info', 'Regenerating task files...');
+			await generateTaskFiles(tasksPath, path.dirname(tasksPath));
+		}
+
+		return convertedTask;
+	} catch (error) {
+		log('error', `Error removing subtask: ${error.message}`);
+		throw error;
+	}
+}
+
+export default removeSubtask;