fix(mobile): keyboard resize:none + web-tunable JS lift (deterministic, no plugin fight)

resize:native gave contradictory results (covered vs header) because the safe-area plugin fights it.
Set resize:none so the native layer does nothing, and lift the composer purely in JS by keyboardHeight
* KB_LIFT. Once resize:none is built, the lift is web-tunable with zero further builds.
Build marker -> 2026-07-18-batch100.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/capacitor.config.json

@@ -17,7 +17,7 @@
       "offsetForKeyboardInsetBug": false
     },
     "Keyboard": {
-      "resize": "native"
+      "resize": "none"
     },
     "SplashScreen": {
       "launchShowDuration": 900,