feat(cli): add skill command for SKILL.md generation (#40)

* feat(mcp-skill): extract skill module to new crate

Phase 1 of generate-skill CLI command implementation:

- Create mcp-skill crate with skill generation logic
- Move parser, context, template modules from mcp-server
- Add validate_server_id() and extract_skill_metadata() functions
- Apply performance fixes (LazyLock for Handlebars template)
- Apply security fixes (path canonicalization, symlink protection)
- Add DoS protection tests (TooManyFiles, FileTooLarge)
- Reduce code duplication between crates

All 564 tests passing.

* feat(cli): add skill command for SKILL.md generation

Add CLI command to generate Claude Code skill files from progressive
loading TypeScript files. Key features:

- Parse JSDoc metadata (@tool, @server, @category, @Keywords, @description)
- Build skill context with automatic categorization and examples
- Multi-layer security: path traversal, symlink, DoS protection
- Refactor main.rs to modular cli.rs/runner.rs structure

The skill command outputs a structured prompt suitable for LLM-based
SKILL.md generation. For optimal results, MCP server is recommended
as it can leverage LLM summarization for more concise output.

* style: fix formatting

* fix: remove unnecessary raw string hashes (clippy)

* fix: use char instead of string in starts_with (clippy)

* fix: allow cast_possible_truncation in test

* fix: update doc examples to use mcp_skill imports

Author: bug-ops

Cargo.lock

@@ -24,11 +24,12 @@ dhat = "0.3"
 dialoguer = "0.12"
 dirs = "6.0"
 handlebars = "6.4"
-mcp-codegen = { path = "crates/mcp-codegen" }
-mcp-core = { path = "crates/mcp-core" }
-mcp-files = { path = "crates/mcp-files" }
-mcp-introspector = { path = "crates/mcp-introspector" }
-mcp-server = { path = "crates/mcp-server" }
+mcp-codegen = { path = "crates/mcp-codegen", version = "0.6.3" }
+mcp-core = { path = "crates/mcp-core", version = "0.6.3"}
+mcp-files = { path = "crates/mcp-files", version = "0.6.3" }
+mcp-introspector = { path = "crates/mcp-introspector", version = "0.6.3"}
+mcp-server = { path = "crates/mcp-server", version = "0.6.3"}
+mcp-skill = { path = "crates/mcp-skill", version = "0.6.3"}
 rayon = "1.11"
 regex = "1.12"
 rmcp = "0.12"

Cargo.toml

@@ -32,6 +32,7 @@ mcp-codegen = { workspace = true }
 mcp-core = { workspace = true }
 mcp-introspector = { workspace = true }
 mcp-files = { workspace = true }
+mcp-skill = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "fs"] }

crates/mcp-cli/Cargo.toml

@@ -160,6 +160,44 @@ mcp-execution-cli introspect --http https://api.example.com/mcp \
   --header "Authorization=Bearer token"
 ```
 
+### `skill`
+
+Generate Claude Code skill files (SKILL.md) from progressive loading tools:
+
+```bash
+mcp-execution-cli skill --server <SERVER_ID> [OPTIONS]
+```
+
+**Options**:
+
+- `--server, -s <ID>`: Server identifier (required)
+- `--servers-dir <PATH>`: Custom servers directory
+- `--output, -o <PATH>`: Custom output path
+- `--skill-name <NAME>`: Custom skill name
+- `--hint <HINT>`: Use case hints (repeatable)
+- `--overwrite`: Overwrite existing SKILL.md
+
+**Examples**:
+
+```bash
+# Generate skill for GitHub server
+mcp-execution-cli skill --server github
+
+# With custom output and hints
+mcp-execution-cli skill --server github \
+  --output ~/.claude/skills/github/SKILL.md \
+  --hint "managing pull requests" \
+  --hint "code review"
+
+# Overwrite existing skill
+mcp-execution-cli skill --server github --overwrite
+```
+
+> [!TIP]
+> For optimal results, prefer using the MCP server (`mcp-server`) for skill generation.
+> The MCP server can leverage LLM capabilities to summarize tool descriptions and reduce
+> context size, resulting in more concise and effective skill files.
+
 ### `stats`
 
 View cache statistics:
@@ -212,6 +250,7 @@ This crate is part of the [mcp-execution](https://github.com/bug-ops/mcp-executi
 - [`mcp-introspector`](../mcp-introspector) - MCP server analysis
 - [`mcp-codegen`](../mcp-codegen) - TypeScript code generation
 - [`mcp-files`](../mcp-files) - Virtual filesystem
+- [`mcp-skill`](../mcp-skill) - Skill generation
 - [`mcp-server`](../mcp-server) - MCP server
 
 ## MSRV Policy