refactor(expand/all): Implement additive expansion and complexity report integration

Refactors the `expandTask` and `expandAllTasks` features to complete subtask 61.38 and enhance functionality based on subtask 61.37's refactor.

Key Changes:

- **Additive Expansion (`expandTask`, `expandAllTasks`):**

    - Modified `expandTask` default behavior to append newly generated subtasks to any existing ones.

    - Added a `force` flag (passed down from CLI/MCP via `--force` option/parameter) to `expandTask` and `expandAllTasks`. When `force` is true, existing subtasks are cleared before generating new ones.

    - Updated relevant CLI command (`expand`), MCP tool (`expand_task`, `expand_all`), and direct function wrappers (`expandTaskDirect`, `expandAllTasksDirect`) to handle and pass the `force` flag.

- **Complexity Report Integration (`expandTask`):**

    - `expandTask` now reads `scripts/task-complexity-report.json`.

    - If an analysis entry exists for the target task:

        - `recommendedSubtasks` is used to determine the number of subtasks to generate (unless `--num` is explicitly provided).

        - `expansionPrompt` is used as the primary prompt content for the AI.

        - `reasoning` is appended to any additional context provided.

    - If no report entry exists or the report is missing, it falls back to default subtask count (from config) and standard prompt generation.

- **`expandAllTasks` Orchestration:**

    - Refactored `expandAllTasks` to primarily iterate through eligible tasks (pending/in-progress, considering `force` flag and existing subtasks) and call the updated `expandTask` function for each.

    - Removed redundant logic (like complexity reading or explicit subtask clearing) now handled within `expandTask`.

    - Ensures correct context (`session`, `mcpLog`) and flags (`useResearch`, `force`) are passed down.

- **Configuration & Cleanup:**

    - Updated `.cursor/mcp.json` with new Perplexity/Anthropic API keys (old ones invalidated).

    - Completed refactoring of `expandTask` started in 61.37, confirming usage of `generateTextService` and appropriate prompts.

- **Task Management:**

    - Marked subtask 61.37 as complete.

    - Updated `.changeset/cuddly-zebras-matter.md` to reflect user-facing changes.

These changes finalize the refactoring of the task expansion features, making them more robust, configurable via complexity analysis, and aligned with the unified AI service architecture.

tasks/task_041.txt

@@ -70,3 +70,65 @@ This implementation should include:
 6. Performance Testing:
    - Measure rendering time for large projects
    - Ensure reasonable performance with 100+ interconnected tasks
+
+# Subtasks:
+## 1. CLI Command Setup [pending]
+### Dependencies: None
+### Description: Design and implement the command-line interface for the dependency graph tool, including argument parsing and help documentation.
+### Details:
+Define commands for input file specification, output options, filtering, and other user-configurable parameters.
+
+## 2. Graph Layout Algorithms [pending]
+### Dependencies: 41.1
+### Description: Develop or integrate algorithms to compute optimal node and edge placement for clear and readable graph layouts in a terminal environment.
+### Details:
+Consider topological sorting, hierarchical, and force-directed layouts suitable for ASCII/Unicode rendering.
+
+## 3. ASCII/Unicode Rendering Engine [pending]
+### Dependencies: 41.2
+### Description: Implement rendering logic to display the dependency graph using ASCII and Unicode characters in the terminal.
+### Details:
+Support for various node and edge styles, and ensure compatibility with different terminal types.
+
+## 4. Color Coding Support [pending]
+### Dependencies: 41.3
+### Description: Add color coding to nodes and edges to visually distinguish types, statuses, or other attributes in the graph.
+### Details:
+Use ANSI escape codes for color; provide options for colorblind-friendly palettes.
+
+## 5. Circular Dependency Detection [pending]
+### Dependencies: 41.2
+### Description: Implement algorithms to detect and highlight circular dependencies within the graph.
+### Details:
+Clearly mark cycles in the rendered output and provide warnings or errors as appropriate.
+
+## 6. Filtering and Search Functionality [pending]
+### Dependencies: 41.1, 41.2
+### Description: Enable users to filter nodes and edges by criteria such as name, type, or dependency depth.
+### Details:
+Support command-line flags for filtering and interactive search if feasible.
+
+## 7. Accessibility Features [pending]
+### Dependencies: 41.3, 41.4
+### Description: Ensure the tool is accessible, including support for screen readers, high-contrast modes, and keyboard navigation.
+### Details:
+Provide alternative text output and ensure color is not the sole means of conveying information.
+
+## 8. Performance Optimization [pending]
+### Dependencies: 41.2, 41.3, 41.4, 41.5, 41.6
+### Description: Profile and optimize the tool for large graphs to ensure responsive rendering and low memory usage.
+### Details:
+Implement lazy loading, efficient data structures, and parallel processing where appropriate.
+
+## 9. Documentation [pending]
+### Dependencies: 41.1, 41.2, 41.3, 41.4, 41.5, 41.6, 41.7, 41.8
+### Description: Write comprehensive user and developer documentation covering installation, usage, configuration, and extension.
+### Details:
+Include examples, troubleshooting, and contribution guidelines.
+
+## 10. Testing and Validation [pending]
+### Dependencies: 41.1, 41.2, 41.3, 41.4, 41.5, 41.6, 41.7, 41.8, 41.9
+### Description: Develop automated tests for all major features, including CLI parsing, layout correctness, rendering, color coding, filtering, and cycle detection.
+### Details:
+Include unit, integration, and regression tests; validate accessibility and performance claims.
+