Initial project structure for MCP interceptors (#3)

Establishes a multi-language monorepo structure for MCP interceptors
with Python and TypeScript SDKs alongside the existing Go
implementation. Implements an efficient CI/CD system that only tests
what changes.


#### 🏗️ SDK Scaffolding
- **Python SDK** (`python/sdk/`): Modern Python package using
`pyproject.toml`, aligned with official MCP Python SDK patterns
- **TypeScript SDK** (`typescript/sdk/`): ESM-based package structure,
compatible with official MCP TypeScript SDK
- **Monorepo structure**: Consistent `{language}/sdk/` pattern across
all implementations
  
 #### 🚀 CI/CD Pipeline
- **Path-based workflow triggering**: Only runs CI for languages that
actually changed
    - Change Python → only Python CI runs
    - Change multiple languages → only those CIs run
- **Status check workflow**: Single required check that dynamically
validates based on changes
- **Comment triggers**: Maintainers can run all checks with `/test all`
PR comment

.gitignore

@@ -1,6 +1,3 @@
-# If you prefer the allow list template instead of the deny list, see community template:
-# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
-#
 # Binaries for programs and plugins
 *.exe
 *.exe~
@@ -30,3 +27,44 @@ go.work.sum
 # Editor/IDE
 # .idea/
 # .vscode/
+
+# Node.js / TypeScript
+node_modules/
+dist/
+*.tsbuildinfo
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+.venv/
+venv/
+ENV/
+.pytest_cache/
+.mypy_cache/
+.ruff_cache/
+htmlcov/
+.coverage
+.coverage.*
+coverage.xml
+*.cover