Add Docker support and integrate /convert-to-docker into setup flow

- Update setup skill to detect platform and offer Docker/Apple Container choice
- On Linux, automatically use Docker via /convert-to-docker skill
- On macOS, ask user preference if Apple Container not installed
- Update README to reflect Docker support and Linux compatibility
- Fix exact line number reference in convert-to-docker skill
- Add thank you to @dotsetgreg for the Docker skill contribution

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -3,7 +3,7 @@
 </p>
 
 <p align="center">
-  My personal Claude assistant that runs securely in Apple containers. Lightweight and built to be understood and customized for your own needs.
+  My personal Claude assistant that runs securely in containers. Lightweight and built to be understood and customized for your own needs.
 </p>
 
 ## Why I Built This
@@ -26,7 +26,7 @@ Then run `/setup`. Claude Code handles everything: dependencies, authentication,
 
 **Small enough to understand.** One process, a few source files. No microservices, no message queues, no abstraction layers. Have Claude Code walk you through it.
 
-**Secure by isolation.** Agents run in Linux containers (Apple Container). They can only see what's explicitly mounted. Bash access is safe because commands run inside the container, not on your Mac.
+**Secure by isolation.** Agents run in Linux containers (Apple Container on macOS, or Docker). They can only see what's explicitly mounted. Bash access is safe because commands run inside the container, not on your host.
 
 **Built for one user.** This isn't a framework. It's working software that fits my exact needs. You fork it and have Claude Code make it match your exact needs.
 
@@ -47,7 +47,7 @@ Then run `/setup`. Claude Code handles everything: dependencies, authentication,
 - **Main channel** - Your private channel (self-chat) for admin control; every other group is completely isolated
 - **Scheduled tasks** - Recurring jobs that run Claude and can message you back
 - **Web access** - Search and fetch content
-- **Container isolation** - Agents sandboxed in Apple containers
+- **Container isolation** - Agents sandboxed in Apple Container (macOS) or Docker (macOS/Linux)
 - **Optional integrations** - Add Gmail (`/add-gmail`) and more via skills
 
 ## Usage
@@ -105,10 +105,10 @@ Skills we'd love to see:
 
 ## Requirements
 
-- macOS Tahoe (26) or later - runs great on Mac Mini
+- macOS or Linux
 - Node.js 20+
 - [Claude Code](https://claude.ai/download)
-- [Apple Container](https://github.com/apple/container)
+- [Apple Container](https://github.com/apple/container) (macOS) or [Docker](https://docker.com/products/docker-desktop) (macOS/Linux)
 
 ## Architecture
 
@@ -133,11 +133,11 @@ Because I use WhatsApp. Fork it and run a skill to change it. That's the whole p
 
 **Why Apple Container instead of Docker?**
 
-Lightweight, fast, and built into macOS. Requires macOS Tahoe and runs great on a Mac Mini. Contribute a skill to convert to Docker if you want Docker.
+On macOS, Apple Container is lightweight, fast, and optimized for Apple silicon. But Docker is also fully supported—during `/setup`, you can choose which runtime to use. On Linux, Docker is used automatically.
 
 **Can I run this on Linux?**
 
-Yes. Run Claude Code and say "make this run on Linux." ~30 min of back-and-forth and it'll work. When you're done, ask Claude to create a skill explaining how to make it work on Linux, then contribute the skill back to the project.
+Yes. Run `/setup` and it will automatically configure Docker as the container runtime. Thanks to [@dotsetgreg](https://github.com/dotsetgreg) for contributing the `/convert-to-docker` skill.
 
 **Is this secure?**