feat: Implement DeepWiki documentation generation tools

- Added `__init__.py` in `codexlens/tools` for documentation generation.
- Created `deepwiki_generator.py` to handle symbol extraction and markdown generation.
- Introduced `MockMarkdownGenerator` for testing purposes.
- Implemented `DeepWikiGenerator` class for managing documentation generation and file processing.
- Added unit tests for `DeepWikiStore` to ensure proper functionality and error handling.
- Created tests for DeepWiki TypeScript types matching.

.claude/skills/spec-generator/templates/product-brief.md

@@ -30,6 +30,15 @@ dependencies:
 
 {executive_summary - 2-3 sentences capturing the essence of the product/feature}
 
+## Concepts & Terminology
+
+| Term | Definition | Aliases |
+|------|-----------|---------|
+| {term_1} | {definition} | {comma-separated aliases if any} |
+| {term_2} | {definition} | |
+
+{Note: All documents in this specification MUST use these terms consistently.}
+
 ## Vision
 
 {vision_statement - clear, aspirational 1-3 sentence statement of what success looks like}
@@ -70,6 +79,15 @@ dependencies:
 - {explicitly excluded item 1}
 - {explicitly excluded item 2}
 
+### Non-Goals
+
+{Explicit list of things this project will NOT do, with rationale for each:}
+
+| Non-Goal | Rationale |
+|----------|-----------|
+| {non_goal_1} | {why this is explicitly excluded} |
+| {non_goal_2} | {why this is explicitly excluded} |
+
 ### Assumptions
 - {key assumption 1}
 - {key assumption 2}
@@ -130,4 +148,6 @@ dependencies:
 | `{product_name}` | Seed analysis | Product/feature name |
 | `{executive_summary}` | CLI synthesis | 2-3 sentence summary |
 | `{vision_statement}` | CLI product perspective | Aspirational vision |
+| `{term_1}`, `{term_2}` | CLI synthesis | Domain terms with definitions and optional aliases |
+| `{non_goal_1}`, `{non_goal_2}` | CLI synthesis | Explicit exclusions with rationale |
 | All `{...}` fields | CLI analysis outputs | Filled from multi-perspective analysis |