docs: add lint command to README and skill

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tae2089

README.md

@@ -227,6 +227,7 @@ Source Code → Tree-sitter Parser → Nodes + Edges + Annotations
 | `ccg example [language]` | Show annotation writing example |
 | `ccg tags` | Show all annotation tag reference |
 | `ccg hooks install` | Install pre-commit git hook |
+| `ccg lint [--out dir]` | Detect orphan, missing, stale docs |
 | `ccg serve` | Start MCP server (stdio) |
 
 ### Config file (`.ccg.yaml`)

skills/ccg.md

@@ -27,6 +27,7 @@ A local code analysis tool that parses codebases via Tree-sitter into a knowledg
 | `example [language]` | Show annotation example for a language | `ccg example go` |
 | `tags` | Show all @tag reference with descriptions | `ccg tags` |
 | `hooks install` | Install pre-commit git hook | `ccg hooks install` |
+| `lint [--out dir]` | Detect orphan, missing, stale docs | `ccg lint --out docs/` |
 | `annotate [file\|dir]` | AI-generate annotations for code | `ccg annotate internal/analysis/` |
 
 ## Execution