fix: block Podman on macOS and remove ghcr.io default (#39)

* fix: block Podman on macOS and remove ghcr.io default

- Add platform check in PodmanCLI.__init__() that raises FuzzForgeError
  on macOS with instructions to use Docker instead
- Change RegistrySettings.url default from "ghcr.io/fuzzinglabs" to ""
  (empty string) for local-only mode since no images are published yet
- Update _ensure_module_image() to show helpful error when image not
  found locally and no registry configured
- Update tests to mock Linux platform for Podman tests
- Add root ruff.toml to fix broken configuration in fuzzforge-runner

* rewrite guides for module architecture and update repo links

---------

Co-authored-by: AFredefon <antoinefredefon@yahoo.fr>

README.md

@@ -72,8 +72,8 @@ Instead of manually running security tools, describe what you want and let your
 
 If you find FuzzForge useful, please **star the repo** to support development! 🚀
 
-<a href="https://github.com/FuzzingLabs/fuzzforge-oss/stargazers">
-  <img src="https://img.shields.io/github/stars/FuzzingLabs/fuzzforge-oss?style=social" alt="GitHub Stars">
+<a href="https://github.com/FuzzingLabs/fuzzforge_ai/stargazers">
+  <img src="https://img.shields.io/github/stars/FuzzingLabs/fuzzforge_ai?style=social" alt="GitHub Stars">
 </a>
 
 ---
@@ -135,8 +135,8 @@ If you find FuzzForge useful, please **star the repo** to support development!
 
 ```bash
 # Clone the repository
-git clone https://github.com/FuzzingLabs/fuzzforge-oss.git
-cd fuzzforge-oss
+git clone https://github.com/FuzzingLabs/fuzzforge_ai.git
+cd fuzzforge_ai
 
 # Install dependencies
 uv sync
@@ -246,7 +246,7 @@ class MySecurityModule(FuzzForgeModule):
 ## 📁 Project Structure
 
 ```
-fuzzforge-oss/
+fuzzforge_ai/
 ├── fuzzforge-cli/           # Command-line interface
 ├── fuzzforge-common/        # Shared abstractions (containers, storage)
 ├── fuzzforge-mcp/           # MCP server for AI agents