docs: add agent working rules and Copilot app configuration

.github/github-app.yml

@@ -0,0 +1,12 @@
+# Repository configuration for the GitHub Copilot app.
+#
+# The authoritative instructions for this repository are in AGENTS.md. This file
+# points at them rather than restating them, so the two cannot drift apart.
+
+instructions: |
+  Read AGENTS.md in the repository root and follow it, starting with the section
+  "Working in this repository". It is the authoritative guidance for this repository.
+
+scripts:
+  - name: Validate
+    command: ruff format --check . && ruff check . && mypy markitdown_mcp/ && pytest tests/unit/

AGENTS.md

@@ -1,17 +1,69 @@
 # AI Agents Integration Guide
 
 This guide provides comprehensive information for AI agents and assistants on how to effectively use the MarkItDown MCP server for document conversion tasks.
 
+## Working in this repository
+
+Read this section before changing anything here. The rest of this file is a usage guide for agents that call the
+server; this section is for agents that change its code.
+
+### Layout
+
+| Path | Purpose |
+|---|---|
+| `markitdown_mcp/` | The server package: `server.py` holds the MCP tools and the `main` entry point |
+| `tests/` | Unit, integration, security, performance and compatibility tests |
+| `schemas/` | Generated tool schemas. Never hand-edit; regenerate with `python scripts/generate-schemas.py` |
+| `docs/` | Guides and API documentation. `docs/api/generated/` is produced by the documentation workflow |
+| `.github/workflows/` | CI, release and maintenance automation. See [`RELEASE.md`](RELEASE.md) for the release pipeline |
+
+### Validate before proposing a change
+
+Set up with `pip install -e ".[dev,test]"`, then run all of these; every one must pass:
+
+```sh
+ruff format --check . && ruff check . && mypy markitdown_mcp/
+pytest tests/unit/
+```
+
+The CI job `Unit Tests & Coverage` runs the same tests, and [`CONTRIBUTING.md`](CONTRIBUTING.md) describes the pull
+request rules. Python 3.10 or later is required and is declared in `pyproject.toml`.
+
+### Do not do these
+
+- Do not rewrite history, force push, or delete branches.
+- Do not commit secrets, tokens, or personal data. Push protection is enabled; a blocked push means stop and tell
+  the maintainer, not retry.
+- Do not create or move tags, publish to PyPI, or run the release workflow. A release is made from a tag by the
+  pipeline described in [`RELEASE.md`](RELEASE.md), and the maintainer starts it.
+- Do not change repository settings, branch protection, or the `pypi` environment. Those are maintainer actions.
+- Do not hand-edit `schemas/*.json` or anything under `docs/api/generated/`; change the source and regenerate.
+- Do not add a dependency without stating why in the pull request.
+- The server reads and writes files on the user's machine. Do not add a code path that reads outside the paths the
+  caller supplies, and do not run `convert_directory` against a directory you were not asked to convert.
+
+### Credentials
+
+The repository holds no long-lived credential. Publishing to PyPI uses trusted publishing from the `pypi`
+environment of `release.yml`, so there is no PyPI token to leak. If that trust is exposed, the maintainer removes
+the publisher on pypi.org and re-adds it. The only other secrets are `GITHUB_TOKEN`, which GitHub issues per run,
+and the optional `GITLEAKS_LICENSE`, which the maintainer replaces in the repository's secret settings.
+
+### Attribution
+
+Commits written by an agent carry a `Co-Authored-By` trailer naming the agent, and every change goes through a pull
+request that a person can review. Nothing is pushed straight to `main`.
+
 ## 🤖 Quick Reference for AI Agents
 
 ### Primary Use Cases
 - Convert documents (PDF, Word, Excel, PowerPoint) to markdown
 - Extract readable text from various file formats
 - Batch process directories of documents
 - Support users with document analysis workflows
 
 ### Available Tools
 1. **`convert_file`** - Convert individual files
 2. **`convert_directory`** - Batch convert directories
 3. **`list_supported_formats`** - Show supported formats
 
@@ -20,12 +72,12 @@
 ### `convert_file` Tool
 
 **When to use:**
 - User provides a file path for conversion
 - User shares base64 content that needs conversion
 - Single document analysis required
 
 **Parameters:**
 ```json
 {
   "file_path": "/path/to/document.pdf",     // For local files
   "file_content": "base64encoded...",      // For shared content
@@ -34,19 +86,19 @@
 ```
 
 **Example scenarios:**
 - "Convert this PDF to markdown"
 - "Extract text from this Word document"
 - "Make this Excel file readable"
 
 ### `convert_directory` Tool
 
 **When to use:**
 - User wants to process multiple files
 - Batch conversion workflows
 - Directory cleanup/organization tasks
 
 **Parameters:**
 ```json
 {
   "input_directory": "/path/to/input",
   "output_directory": "/path/to/output"    // Optional