fix(data): align android_keystore temp extension with cleanup glob (M-21)

The keystore atomic write used path.with_extension("tmp") producing
auth_tokens.tmp, while cleanup_orphaned_tmp_files only matched *.json.tmp.
A crash after the write but before the rename left an orphaned file
invisible to cleanup.

Fix: use path.with_extension("bin.tmp") to produce auth_tokens.bin.tmp,
and broaden the cleanup glob from ends_with(".json.tmp") to
ends_with(".tmp") so both JSON and binary temp files are caught.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_data/src/android_keystore.rs

@@ -295,9 +295,9 @@ fn read_file_bytes() -> Result<Vec<u8>, TokenError> {
 fn write_file_bytes(data: &[u8]) -> Result<(), TokenError> {
     let path = token_file_path()
         .ok_or_else(|| TokenError::KeychainUnavailable("no data dir".into()))?;
-    let tmp = path.with_extension("tmp");
+    let tmp = path.with_extension("bin.tmp");
     std::fs::write(&tmp, data)
-        .map_err(|e| TokenError::Keyring(format!("write auth_tokens.tmp: {e}")))?;
+        .map_err(|e| TokenError::Keyring(format!("write auth_tokens.bin.tmp: {e}")))?;
     std::fs::rename(&tmp, &path)
         .map_err(|e| TokenError::Keyring(format!("rename auth_tokens: {e}")))
 }

solitaire_data/src/storage.rs

@@ -122,7 +122,7 @@ pub fn delete_game_state_at(path: &Path) -> io::Result<()> {
     }
 }
 
-/// Remove any leftover `*.json.tmp` files in the app data directory.
+/// Remove any leftover `*.tmp` files in the app data directory.
 ///
 /// These can be left behind if the process crashes between the write and rename
 /// in an atomic save. Safe to call on startup; missing or unreadable entries
@@ -266,7 +266,7 @@ pub fn time_attack_session_with_now(remaining_secs: f32, wins: u32) -> TimeAttac
     }
 }
 
-/// Inner helper: delete `*.json.tmp` entries inside `dir`.
+/// Inner helper: delete `*.tmp` entries inside `dir`.
 ///
 /// Per-file errors (already deleted, permission denied) are silently ignored.
 fn cleanup_tmp_files_in(dir: &Path) {
@@ -276,7 +276,7 @@ fn cleanup_tmp_files_in(dir: &Path) {
             if path
                 .file_name()
                 .and_then(|n| n.to_str())
-                .is_some_and(|n| n.ends_with(".json.tmp"))
+                .is_some_and(|n| n.ends_with(".tmp"))
             {
                 let _ = fs::remove_file(&path);
             }