feat(studio): first-run UX, recovery affordances, l10n, bundled fonts

- Connection-aware Welcome: when the hub is down, show a hero with a
  primary "Start hub" CTA + install fallback instead of a dead,
  all-unchecked onboarding checklist (the first-run cliff).
- Actionable binary-not-found (file picker + install link, not a
  "set FAI_BIN" dead end) and a connect-failure banner after
  repeated failed health polls.
- Localize six hardcoded English error/toast clusters (DE+EN ARB).
- Bundle Inter + JetBrains Mono as assets; drop the runtime
  google_fonts fetch (air-gap / KRITIS safe, no font-swap flash).

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

linux/flutter/generated_plugins.cmake

@@ -7,7 +7,6 @@ list(APPEND FLUTTER_PLUGIN_LIST
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST
-  jni
 )
 
 set(PLUGIN_BUNDLED_LIBRARIES)