Update README.md for Quick Connect, RDP clipboard sync, latest release

README.md hadn't been touched since v2026.9.16.7 and had drifted:
Quick Connect (issue #23) was undocumented, RDP's own clipboard sync
was missing from its feature list (only VNC's was listed), and the
"latest release" pointed at a stale version with a note about a draft
that has long since published.

Also adds CLAUDE.md with a release checklist so README.md gets checked
for drift as a standard part of every release going forward, per user
request, instead of falling behind until someone notices.

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

CLAUDE.md

@@ -0,0 +1,20 @@
+# OrbitHub
+
+## Release checklist
+
+Every release (new tag + build + publish) must include:
+
+- **Update `README.md`** to match current reality before tagging:
+  latest published release version/link, the Implemented Features list
+  (add/adjust bullets for anything shipped since the last release), and
+  any status notes (e.g. VNC/Apple-auth caveats) that changed.
+- Update `docs/PROGRESS.md` with a bullet describing what shipped.
+- Bump the version in `CMakeLists.txt`.
+- Build and test all reachable platforms (Linux local, Windows and macOS
+  over SSH — see prior release commits/sessions for the build scripts
+  used) before publishing.
+
+`docs/USER_GUIDE.md` (in-app `Help -> User Guide` and the release PDF)
+should also be checked for drift when a change affects user-facing
+behavior, though it doesn't need a pass on every single release the way
+README.md does.