fix: resolve ruff lint errors in mcp() command (F821, B904, I001) (#30)

* chore: harden .gitignore with merge artifacts, cache, and common exclusions

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

* chore: add standard project scaffolding (gitattributes, dependabot, SECURITY, pre-commit, ISSUE_TEMPLATE, CHANGELOG, LICENSE)

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

* fix: resolve ruff lint errors in mcp() command (F821, B904, I001)

- Replace undefined 'typer' references with 'click.echo' and 'raise SystemExit(1) from None'
- Fix unsorted imports in _render_costs() (I001)
- deploydiff uses Click, not Typer

---------

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

Author: Coding-Dev-Tools

.gitignore

@@ -71,3 +71,15 @@ Thumbs.db
 research/
 fixtures/generated/
 .ruff_cache/
+
+# Merge artifacts and cache (added by workspace stabilization)
+*.pyc
+*.pyo
+*.pyd
+*.orig
+*.BACKUP.*
+*.BASE.*
+*.LOCAL.*
+*.REMOTE.*
+local.db
+*.sqlite3

.pre-commit-config.yaml

@@ -0,0 +1,17 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-toml
+      - id: check-added-large-files
+      - id: detect-private-key
+
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.12.0
+    hooks:
+      - id: ruff
+        args: ["--fix"]
+      - id: ruff-format

src/deploydiff/cli.py

@@ -114,6 +114,21 @@ def rollback(terraform_file, cloudformation_file, pulumi_file) -> None:
         console.print(cmd)
 
 
+@main.command()
+def mcp():
+    """Run as an MCP (Model Context Protocol) server over stdio.
+
+    AI coding agents (Claude Code, Cursor, etc.) use this to interact
+    with deploydiff tools directly.
+    """
+    try:
+        from click_to_mcp import serve_stdio
+    except ImportError:
+        click.echo("Error: click-to-mcp is required for MCP support. Install with: pip install click-to-mcp", err=True)
+        raise SystemExit(1) from None
+    serve_stdio(main, name="deploydiff")
+
+
 def _load_plan(
     terraform_file: str | None,
     cloudformation_file: str | None,