fix(expand-task): include parent task context in complexity report variant (#1094)

- Fixed bug where expand task generated generic authentication subtasks
- The complexity-report prompt variant now includes parent task details
- Added comprehensive unit tests to prevent regression
- Added debug logging to help diagnose similar issues

Previously, when using a complexity report with expansionPrompt, only the
expansion guidance was sent to the AI, missing the actual task context.
This caused the AI to generate unrelated generic subtasks.

Fixes the issue where all tasks would get the same generic auth-related
subtasks regardless of their actual purpose (AWS infrastructure, Docker
containerization, etc.)

Co-authored-by: Sadaqat Ali <32377500+sadaqat12@users.noreply.github.com>

src/prompts/expand-task.json

@@ -69,7 +69,7 @@
 		"complexity-report": {
 			"condition": "expansionPrompt",
 			"system": "You are an AI assistant helping with task breakdown. Generate {{#if (gt subtaskCount 0)}}exactly {{subtaskCount}}{{else}}an appropriate number of{{/if}} subtasks based on the provided prompt and context.\nRespond ONLY with a valid JSON object containing a single key \"subtasks\" whose value is an array of the generated subtask objects.\nEach subtask object in the array must have keys: \"id\", \"title\", \"description\", \"dependencies\", \"details\", \"status\".\nEnsure the 'id' starts from {{nextSubtaskId}} and is sequential.\nFor 'dependencies', use the full subtask ID format: \"{{task.id}}.1\", \"{{task.id}}.2\", etc. Only reference subtasks within this same task.\nEnsure 'status' is 'pending'.\nDo not include any other text or explanation.",
-			"user": "{{#if isClaudeCode}}## IMPORTANT: Codebase Analysis Required\n\nYou have access to powerful codebase analysis tools. Before generating subtasks:\n\n1. Use the Glob tool to explore relevant files for this task (e.g., \"**/*.js\", \"src/**/*.ts\")\n2. Use the Grep tool to search for existing implementations related to this task\n3. Use the Read tool to examine files that would be affected by this task\n4. Understand the current implementation state and patterns used\n\nBased on your analysis:\n- Identify existing code that relates to this task\n- Understand patterns and conventions to follow\n- Generate subtasks that integrate smoothly with existing code\n- Ensure subtasks are specific and actionable based on the actual codebase\n\nProject Root: {{projectRoot}}\n\n{{/if}}{{expansionPrompt}}{{#if additionalContext}}\n\n{{additionalContext}}{{/if}}{{#if complexityReasoningContext}}\n\n{{complexityReasoningContext}}{{/if}}{{#if gatheredContext}}\n\n# Project Context\n\n{{gatheredContext}}{{/if}}"
+			"user": "Break down the following task based on the analysis prompt:\n\nParent Task:\nID: {{task.id}}\nTitle: {{task.title}}\nDescription: {{task.description}}\nCurrent details: {{#if task.details}}{{task.details}}{{else}}None{{/if}}\n\nExpansion Guidance:\n{{expansionPrompt}}{{#if additionalContext}}\n\n{{additionalContext}}{{/if}}{{#if complexityReasoningContext}}\n\n{{complexityReasoningContext}}{{/if}}{{#if gatheredContext}}\n\n# Project Context\n\n{{gatheredContext}}{{/if}}\n\nGenerate {{#if (gt subtaskCount 0)}}exactly {{subtaskCount}}{{else}}an appropriate number of{{/if}} subtasks with sequential IDs starting from {{nextSubtaskId}}."
 		},
 		"research": {
 			"condition": "useResearch === true && !expansionPrompt",