docs: Improve MCP tool descriptions for clarity and completeness

- smart_search: Condense verbose description from 40 to 12 lines while preserving key usage examples
- write_file: Add missing createDirectories parameter documentation
- edit_file: Clarify update/line mode naming and add batch edit examples

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ccw/src/tools/write-file.ts

@@ -105,7 +105,7 @@ export const schema: ToolSchema = {
   description: `Write content to file. Auto-creates parent directories.
 
 Usage: write_file(path="file.js", content="code here")
-Options: backup=true (backup before overwrite), encoding="utf8"`,
+Options: backup=true (backup before overwrite), createDirectories=false (disable auto-creation), encoding="utf8"`,
   inputSchema: {
     type: 'object',
     properties: {