docs: close out Milestone 7 (cross-platform protocol hardening)

Linux, macOS, and Windows have all been validated against the current
feature set (SSH, RDP display/keyboard/clipboard/cursor, Tab forwarding,
key repeat, profile dialog, single-window UI), with the platform-specific
bugs found along the way fixed and tracked individually on the issue
tracker (#8-#16). VNC validation remains out of scope while Milestone 6
stays deferred.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -13,7 +13,7 @@ Supported target platforms:
 
 OrbitHub is in active development.
 
-- Milestones completed: M0-M5 and M8
+- Milestones completed: M0-M5, M7, and M8
 - Current milestone: Milestone 9 (Packaging and Distribution)
 - Deferred milestone: Milestone 6 (VNC Fully Working)
 - Latest checkpoint tag: `v0-m8-done`

docs/PROGRESS.md

@@ -115,12 +115,40 @@ Planned Scope:
 
 ## Milestone 7 - Cross-Platform Protocol Hardening
 
-Status: Planned
+Status: Completed
 
-Planned Scope:
-- Validate SSH/RDP/VNC workflows on Windows, Linux, and macOS
-- Fix platform-specific runtime/process/auth issues
-- Add repeatable protocol validation checklist/scripts
+Delivered:
+- Validated SSH and RDP workflows on Linux, macOS, and Windows 11 (VNC is out
+  of scope while Milestone 6 remains deferred)
+- Windows: validated the full `docs/BUILDING.md` toolchain end-to-end
+  (Git/CMake/Ninja/VS Build Tools with the C++ workload/vcpkg for
+  Qt6-OpenSSL-zlib); documented a VS Build Tools installer gotcha where the
+  actual compiler is a "recommended", not "required", component of the
+  VCTools workload
+- Fixed RDP keyboard input misreading punctuation keys on Linux (X11 keycode
+  numbering was being treated as a PC/AT scancode; now uses FreeRDP's
+  authoritative X11-keycode-to-scancode table)
+- Added RDP clipboard sync (bidirectional, plain text) and RDP cursor/pointer
+  shape sync (resize handles, text I-beam, etc. instead of a static arrow)
+- Fixed Tab/Shift+Tab being intercepted by local UI focus navigation instead
+  of reaching SSH/RDP sessions
+- Fixed RDP key auto-repeat being dropped, so holding a key only ever sent a
+  single keystroke to the remote machine
+- Windows-specific RDP fixes: a crash on every connect attempt (FreeRDP's
+  signal-handling critical section was never initialized) and a host
+  resolution failure on every connect, including literal IP addresses
+  (Winsock was never initialized via `WSAStartup`)
+- Windows: automatic build-time deployment of Qt's platform/SQL-driver
+  plugins and their runtime DLL dependencies, and marked the executable as a
+  GUI (`WIN32`) app to remove a stray console window behind the UI
+- Windows and macOS: proper native app icon embedding (Windows `.rc`/`.ico`
+  resource; macOS `.app` bundle with `.icns`), replacing the generic default
+  icon previously shown for the built executable/bundle
+- macOS: fixed Edit/New Profile dialog form fields collapsing to `sizeHint`
+  width due to the platform-default `QFormLayout` field growth policy
+
+Git:
+- Tag: Pending user approval (`v0-m7-done`)
 
 ## Milestone 8 - Profile and Session UX Completion