Merge: a log that survives the process, so the tablet can be debugged

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

# Conflicts:
#	apps/darkroom-android/Cargo.toml
#	apps/darkroom-desktop/Cargo.toml
#	platform/dr-plat/src/lib.rs

platform/dr-plat/src/lib.rs

@@ -4,18 +4,21 @@
 //! construction, so `core/` contains no `#[cfg(target_os)]` (NFR-PORT-1,
 //! ARCH §10).
 
-// Not a trait, and the one module here that is not. It belongs in this crate
-// for the same reason the traits do: "where does this platform let an
-// application keep state" is a platform question, and both entry points need
-// the answer before either has a window. Resolving it in `apps/` would mean
-// writing it twice, once per platform, which is the arrangement this crate
-// exists to prevent.
+// Neither of the next two is a trait, and they are the modules here that are
+// not. They belong in this crate for the same reason the traits do: "where does
+// this platform let an application keep state" is a platform question, and both
+// entry points need the answer before either has a window. Resolving it in
+// `apps/` would mean writing it twice, once per platform, which is the
+// arrangement this crate exists to prevent.
 pub mod crash;
+pub mod diagnostics;
 pub mod display;
 pub mod secrets;
+pub mod state;
 pub mod storage;
 pub mod volumes;
 
+pub use diagnostics::{Installed, LogFile};
 pub use display::{
     Bounds, DisplayInfo, DisplayProfile, DisplayServer, DisplaySurvey, FallbackReason,
     ProfileSource,
@@ -23,6 +26,7 @@ pub use display::{
 pub use secrets::{
     EphemeralSecretStore, PlatformSecretStore, SecretError, SecretKind, SecretRef, SecretStore,
 };
+pub use state::{set_state_dir, state_dir};
 pub use storage::{
     DirRef, Entry, LocalStorage, NewFile, Node, SeekableRead, Storage, StorageError,
     WritableStorage,