Document post-M4 roadmap with separate RDP and VNC milestones

docs/PROGRESS.md

@@ -77,4 +77,60 @@ Delivered:
 - Terminal behavior polish: better fixed-width font selection, cursor visibility, backspace handling, and terminal-size negotiation stability
 
 Git:
-- Tag: `v0-m4-done` (pending push)
+- Tag: `v0-m4-done`
+
+## Milestone 5 - RDP MVP Connectivity
+
+Status: Planned
+
+Planned Scope:
+- Replace current unsupported RDP backend behavior with a real RDP connection flow
+- Implement RDP connect/disconnect/reconnect lifecycle handling
+- Extend profile/session connect options needed by RDP
+- Standardize event log and error mapping behavior with SSH
+
+## Milestone 6 - VNC MVP Connectivity
+
+Status: Planned
+
+Planned Scope:
+- Replace current unsupported VNC backend behavior with a real VNC connection flow
+- Implement VNC connect/disconnect/reconnect lifecycle handling
+- Extend profile/session connect options needed by VNC
+- Standardize event log and error mapping behavior with SSH/RDP
+
+## Milestone 7 - Cross-Platform Protocol Hardening
+
+Status: Planned
+
+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
+
+## Milestone 8 - Profile and Session UX Completion
+
+Status: Planned
+
+Planned Scope:
+- Complete protocol-aware profile validation and UX polish
+- Add/persist session UI preferences and default behaviors
+- Improve events/diagnostics visibility for long-running session usage
+
+## Milestone 9 - Packaging and Distribution
+
+Status: Planned
+
+Planned Scope:
+- Build distributable artifacts for Windows/Linux/macOS
+- Document runtime dependencies and install prerequisites
+- Add reproducible release packaging steps/scripts
+
+## Milestone 10 - v1.0 Stabilization
+
+Status: Planned
+
+Planned Scope:
+- Run final regression and acceptance testing across all protocols
+- Resolve release-blocking defects
+- Finalize docs and publish v1.0 release notes/checklist