Reorganize Firefox configuration and repository documentation

- Configure Firefox with privacy settings and extensions (Bitwarden, Plasma Integration, MetaMask, Kagi Search, uBlock Origin)
- Set Kagi as default/only search engine
- Add MOZ_USE_XINPUT2=1 for smooth scrolling
- Create context/ directory for concise unit documentation
- Create tests/ directory for test scripts
- Move test-firefox-config.sh to tests/
- Update agents.md with documentation workflow guidelines
- Fix syntax errors in desktop.nix and dev.nix

context/README.md

@@ -0,0 +1,73 @@
+# Context Directory
+
+This directory contains concise documentation for discrete units of work performed in this repository.
+
+## Purpose
+Document specific configurations, changes, and procedures in a concise format. Prefer clarity over verbosity - use inline comments in code when the config is self-documenting.
+
+## Organization
+
+### File Naming
+- Use lowercase, hyphenated names
+- Include dates for time-sensitive updates: `feature-update-YYYY-MM-DD.md`
+- Use descriptive names for ongoing configs: `service-name.md`
+
+### File Content
+Each file should document:
+- **What** changes were made
+- **Where** the config lives (file paths)
+- **How** to build/test/deploy
+- **Why** the change was made (brief context)
+
+## Examples
+
+### Service Configuration
+```markdown
+# Service Name
+
+**Config:** `servers/service-name.nix`
+
+## Purpose
+Brief description of what this service does.
+
+## Build & Deploy
+```bash
+nixos-rebuild build --flake .#system
+```
+
+## Notes
+Key points to remember.
+```
+
+### Event/Update Documentation
+```markdown
+# Feature Update - YYYY-MM-DD
+
+## Changes
+- Removed: old-feature
+- Added: new-feature
+
+## Resolution
+How the issue was solved.
+
+## Build
+Build commands if relevant.
+```
+
+## When to Create Files
+- Major feature additions to services/desktop configs
+- Significant refactoring or restructuring
+- Security updates requiring special handling
+- Cross-service dependencies
+- Troubleshooting guides for complex issues
+
+## When NOT to Create Files
+- Routine package updates
+- Self-documenting NixOS configurations
+- Trivial changes covered by code comments
+- Temporary debugging (use git commits instead)
+
+## Related Documentation
+- `agents.md` - Agent instructions and procedures
+- `README.md` - Project overview
+- Test scripts in `tests/`