fix: update sdk_version to 6.18.0 in README.md frontmatter

feat: unified Wilderness AI chatbot & 1s GPS updates with proximity highlights

integrate gps features and clean UI

docs: update README with Android installation steps and current progress

fix: resolve schema typeerror by upgrading gradio to 5.15.0 and refactoring handlers

Pin Python version to 3.11 in Hugging Face Space metadata

Remove Docker support, configure Hugging Face for Gradio SDK, add database.py, stage background map tile downloader

Add Hugging Face Space metadata to README.md

Update README.md with current state of Phase 2 features

Initial commit: Set up Trailhead structure, Docker, README, and .gitignore