Offline Work mode + Reconcile Offline Work dialog, menu tooltips, spinner fix; v0.3.0

- Explicit Work Offline toggle (P4V-style): stops server polling, calm offline banner, persisted
- Reconcile Offline Work dialog: preview adds/edits/deletes with per-file checkboxes, opens picked into a changelist
- Make writable (offline edit) context action; backend p4_reconcile_preview/apply + p4_set_writable
- Tooltips (title) on every top-menu item, 5 languages
- Fix .ldr spinner rendering (inline-block + box-sizing) so it's a clean circle everywhere

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "exbyte-depot"
-version = "0.2.4"
+version = "0.3.0"
 description = "Exbyte Depot — native Perforce client by Exbyte Studios"
 authors = ["Exbyte Studios"]
 edition = "2021"