feat(android): mark the clipboard sensitive, and lock after 3 min idle

Since Android 13 the system shows a preview of whatever was just copied, at the bottom of the screen. For a password that is precisely what we are trying to avoid: it appears in clear, outside the app, for several seconds. The flag that suppresses it is a ClipDescription extra, which IFMXClipboardService does not expose - hence going straight to ClipboardManager. Note Jcontent_ClipboardManager, not JClipboardManager: the latter is the deprecated android.text one, which knows only bare text and has no ClipData to carry an extra.

Backgrounding already locks; the idle timer covers the phone left face-up on a table with the app open. It samples timestamps every 15 s rather than counting seconds - a wake-up per second would cost battery for no precision that matters.

Attachments dropped from the plan: this vault has none.

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

pmserverApk.dpr

@@ -11,7 +11,8 @@ uses
   PMA.Biometric in 'android-client\PMA.Biometric.pas',
   PMA.Vault in 'android-client\PMA.Vault.pas',
   PMA.Totp in 'android-client\PMA.Totp.pas',
-  PMA.ScreenGuard in 'android-client\PMA.ScreenGuard.pas';
+  PMA.ScreenGuard in 'android-client\PMA.ScreenGuard.pas',
+  PMA.Clipboard in 'android-client\PMA.Clipboard.pas';
 
 {$R *.res}