The store's layout names live in the core: local::DB_FILE, BLOBS_DIR

"inkwell.db" and "blobs" were spelled out in the ffi and the desktop (whose copy
of DB_FILE sat in the crossover shim). The layout is the core's, the same on
every client, so the names are now core constants and both clients read them.

DRY pass #2, batch 1, F4 (#5372).

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

desktop/src-tauri/src/crossover.rs

@@ -19,11 +19,12 @@ use std::fs;
 use std::io;
 use std::path::Path;
 
+use inkwell_core::local::DB_FILE;
+
 /// The identifier ThoughtSync shipped under. Its app-data dir is a sibling of ours.
 pub const LEGACY_IDENTIFIER: &str = "com.fabledsword.thoughtsync";
 
 const LEGACY_DB: &str = "thoughtsync.db";
-pub const DB_FILE: &str = "inkwell.db";
 
 /// What a crossover did, for the startup log.
 #[derive(Debug, PartialEq, Eq)]