remove dead code

docs/TODO.md

@@ -0,0 +1,19 @@
+# TODO
+
+Deferred from `docs/over-engineering-cleanup-plan.md`.
+
+## `BackendEvent::SyncProgress`
+
+File: `crates/signed_state/src/backend.rs`
+
+The variant has no subscriber. Remove the variant, the `sync_progress` field and
+its accessor, and the `progress_task` in `sync_bootstrap`. Keep the terminal
+`Synced` emission.
+
+## `login` / `logout` family
+
+File: `crates/signed_state/src/backend.rs`
+
+No UI path calls these. `import_dialog::open` is an empty stub. Decide whether to
+delete the family (`login`, `login_with_new_identity`, `login_with_nsec`,
+`login_with_bunker`, `logout`) or wire the stub to `Backend::login`.