feat(android): settings live on the device, dark theme, and the app is called Coffre

URL and token are no longer constants. They sit in settings.bin, sealed with the no-auth Keystore AES key - deliberately weaker than the vault: they must be readable to rebuild a vault that no longer exists, and a bearer token only opens ENCRYPTED data, worthless without the sync password that stays in the guarded vault. Retyping 64 hex characters after every cache purge was the real risk: the risk of writing them down elsewhere. They are saved only after a fetch that worked - proven settings, not typed ones.

The token and sync password moved to the gitignored local include, as first-run defaults only. Tracked source now carries no secret, and leaving them empty is a viable configuration: the app asks.

Theme: Delphi's Dark.style, copied into the repo and linked as a resource rather than deployed as a file - this project's deployment puts nothing beside the app, which is the same hole that forces the manifest and dex staging. A failure to load is never fatal; the default look is ugly but works.

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

android-client/theme/theme.rc

@@ -0,0 +1 @@
+PMDARKSTYLE RCDATA "pm-dark.style"