Record Milestone 0 completion progress

docs/PROGRESS.md

@@ -0,0 +1,17 @@
+# OrbitHub Progress
+
+## Milestone 0 - Restart in C++/Qt Widgets
+
+Status: Completed
+
+Delivered:
+- Fresh C++17/Qt6 Widgets scaffold with CMake
+- `ProfilesWindow` (`QMainWindow`) with search, profile list, and New/Edit/Delete controls
+- Double-click in Profiles opens a `SessionWindow`
+- `SessionWindow` (`QMainWindow`) with `QTabWidget`
+- Placeholder tab content showing `OrbitHub Native Surface`
+- `main.cpp` wiring for application startup
+
+Git:
+- Branch: `milestone-0-restart-cpp`
+- Tag: `v0-m0-done`