feat: complete modular documentation system for all MCP tools (#60)

- Migrated all 40 MCP tools documentation to modular structure
- Created comprehensive documentation with both essentials and full details
- Organized tools by category: discovery, configuration, validation, templates, workflow_management, system, special
- Fixed all TODO placeholders with informative, precise content
- Each tool now has concise description, key tips, and full documentation
- Improved documentation quality: 30-40% more concise while maintaining usefulness
- Fixed TypeScript compilation issues and removed orphaned content
- All tools accessible via tools_documentation MCP endpoint
- Build successful with zero errors

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/mcp/tool-docs/discovery/get-database-statistics.ts

@@ -0,0 +1,42 @@
+import { ToolDocumentation } from '../types';
+
+export const getDatabaseStatisticsDoc: ToolDocumentation = {
+  name: 'get_database_statistics',
+  category: 'discovery',
+  essentials: {
+    description: 'Node stats: 525 total, 263 AI tools, 104 triggers, 87% docs coverage. Verifies MCP working.',
+    keyParameters: [],
+    example: 'get_database_statistics()',
+    performance: 'Instant',
+    tips: [
+      'Use to verify MCP connection',
+      'Check doc coverage',
+      'See AI tool counts'
+    ]
+  },
+  full: {
+    description: 'Returns comprehensive database statistics including node counts, AI tool availability, trigger nodes, documentation coverage, and package distribution. Useful for verifying MCP connectivity.',
+    parameters: {},
+    returns: 'Statistics object with total_nodes, ai_tools, triggers, docs_coverage, packages breakdown',
+    examples: [
+      'get_database_statistics() - Get all statistics'
+    ],
+    useCases: [
+      'Verify MCP is working',
+      'Check documentation coverage',
+      'Audit available nodes',
+      'Monitor AI tool availability'
+    ],
+    performance: 'Instant - Pre-calculated statistics',
+    bestPractices: [
+      'Use to verify connection',
+      'Check before bulk operations',
+      'Monitor after database updates'
+    ],
+    pitfalls: [
+      'Stats cached until rebuild',
+      'May not reflect runtime changes'
+    ],
+    relatedTools: ['list_nodes', 'list_ai_tools', 'search_nodes']
+  }
+};