Clean up documentation structure

docs/README.md

@@ -0,0 +1,29 @@
+# Documentation
+
+This folder contains project documentation for Overland Controller.
+
+## Primary Documents
+
+- `API.md` - HTTP API reference
+- `SERIAL_COMMANDS.md` - Serial console command reference
+- `HARDWARE.md` - Hardware overview
+- `ARCHITECTURE.md` - System architecture
+- `CHANGELOG.md` - Project change history
+
+## Project Tracking
+
+- `project-state.md` - Current project state
+- `roadmap.md` - Roadmap and future plans
+- `hardware-status.md` - Hardware status and bring-up notes
+- `decisions.md` - Architecture and implementation decisions
+
+## Technical References
+
+- `protocol.md` - Dashboard/controller protocol
+- `wiring.md` - Wiring notes and plans
+
+## Archive
+
+Older or duplicate documents have been moved to `archive/`.
+
+Archived documents are kept for history, but the primary documents above should be treated as the current source of truth.