chore: extract ShareServer into its own repository

Move the existing Hono API, React console, tests, build configuration,
and feature documentation from GoodBuddy into a standalone project.
Keep the current interactive-prototype behavior and production limitations.

Document the source commit and sibling-checkout links to the authoritative
Desktop network architecture. Independent install, tests, typecheck, lint,
build, and built-service HTTP smoke checks passed.

.gitignore

@@ -0,0 +1,4 @@
+build-server/
+dist/
+node_modules/
+*.png