fix: stop exporting DecryptActivity and validate decrypt paths

DecryptActivity was exported without an intent filter, so any installed
app could start it with arbitrary FILE_PATH/REPO_PATH extras (and crash
it by omitting them). Nothing outside the app needs to launch it:
shortcuts and the decrypt action go through LaunchActivity.

LaunchActivity stays exported, so it now treats FILE_PATH as untrusted:
the path is forwarded only when it canonically resolves to a regular
file inside the password store, and REPO_PATH is always the real store
directory instead of the caller-supplied value. Anything else falls
back to the main screen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions