docs: Add comprehensive documentation and update planning

- Add docs/README.md with project overview and current status
- Add docs/architecture.md with detailed architecture documentation
- Add docs/development.md with development guide for contributors
- Update .notes/todo.md to reflect architecture fix completion
- Update .notes/plan.md with completed phases and next priorities

Architecture fixes (daemon and dbus), bubblewrap integration are now complete.
Ready for OCI integration phase.

test-architecture.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+# Test apt-ostree Architecture Fix
+
+set -e
+
+echo "=== Testing apt-ostree Architecture Fix ==="
+echo
+
+# Check if daemon is running
+echo "1. Checking if daemon is running..."
+if systemctl is-active --quiet apt-ostreed.service; then
+    echo "✓ Daemon is running"
+else
+    echo "⚠ Daemon is not running - will test fallback mode"
+fi
+
+echo
+
+# Test daemon ping
+echo "2. Testing daemon ping..."
+if sudo apt-ostree daemon-ping 2>/dev/null; then
+    echo "✓ Daemon ping successful"
+else
+    echo "⚠ Daemon ping failed - daemon may not be running"
+fi
+
+echo
+
+# Test daemon status
+echo "3. Testing daemon status..."
+if sudo apt-ostree daemon-status 2>/dev/null; then
+    echo "✓ Daemon status successful"
+else
+    echo "⚠ Daemon status failed - daemon may not be running"
+fi
+
+echo
+
+# Test command fallback (without daemon)
+echo "4. Testing command fallback (without daemon)..."
+if systemctl is-active --quiet apt-ostreed.service; then
+    echo "Stopping daemon to test fallback..."
+    sudo systemctl stop apt-ostreed.service
+    sleep 2
+fi
+
+# Test status command fallback
+echo "Testing status command fallback..."
+if apt-ostree status 2>/dev/null; then
+    echo "✓ Status command fallback successful"
+else
+    echo "⚠ Status command fallback failed"
+fi
+
+echo
+
+# Test search command fallback
+echo "Testing search command fallback..."
+if apt-ostree search test 2>/dev/null; then
+    echo "✓ Search command fallback successful"
+else
+    echo "⚠ Search command fallback failed"
+fi
+
+echo
+
+# Restart daemon if it was running
+echo "5. Restarting daemon if it was previously running..."
+if systemctl is-enabled --quiet apt-ostreed.service; then
+    sudo systemctl start apt-ostreed.service
+    echo "✓ Daemon restarted"
+else
+    echo "⚠ Daemon not enabled - skipping restart"
+fi
+
+echo
+
+echo "=== Architecture Test Complete ==="
+echo "Summary:"
+echo "- Daemon-based commands should work when daemon is running"
+echo "- Commands should fallback to client-only when daemon is unavailable"
+echo "- This provides proper rpm-ostree architecture compatibility"