diff --git a/crates/lash-tui/tests/activity_bar_tests.rs b/crates/lash-tui/tests/activity_bar_tests.rs
new file mode 100644
index 0000000..634d249
--- /dev/null
+++ b/crates/lash-tui/tests/activity_bar_tests.rs
@@ -0,0 +1,167 @@
+//! Integration tests for the status-bar activity sections.
+//!
+//! These cover the two cases `tasks/tasks.status-bar-activity.md` left
+//! deferred for want of a TUI harness that did not exist yet: the ordering
+//! `seed_from_db` uses to pick between several in-progress tasks, and a
+//! toggle driven through the real key path rather than through
+//! `ActivityState::record_transition` directly.
+
+use lash_tui::activity::ActivityState;
+use lash_tui::testing::{keys, TestAppBuilder};
+use std::path::PathBuf;
+use std::time::Instant;
+use tempfile::TempDir;
+
+/// Build a project containing `body` and index it, returning the temp dir
+/// (which must outlive the test), the db path, and the task file path.
+fn setup_project(body: &str) -> (TempDir, PathBuf) {
+    let temp_dir = TempDir::new().unwrap();
+    let project_root = temp_dir.path().to_path_buf();
+    std::fs::create_dir(project_root.join(".lash")).unwrap();
+    let db_path = project_root.join(".lash").join("lash.db");
+
+    let conn = lash_db::init_database(&db_path).unwrap();
+    std::fs::write(project_root.join("tasks.md"), body).unwrap();
+
+    use lash_db::{Indexer, IndexerConfig};
+    let parser_config = lash_types::LashConfig::default();
+    let indexer_config = IndexerConfig::new(project_root).with_progress(false);
+    let mut indexer = Indexer::new(&conn, indexer_config, &parser_config);
+    indexer.index_project().unwrap();
+
+    (temp_dir, db_path)
+}
+
+#[test]
+fn seeding_picks_the_smaller_full_id_when_several_tasks_are_in_progress() {
+    // Two in-progress tasks, written in the order that would give the wrong
+    // answer if seeding took whichever the DB happened to return first:
+    // `zulu` is above `alpha` in the file, so insertion order and full_id
+    // order disagree.
+    let (_temp_dir, db_path) = setup_project(
+        r"# Sample
+
+@id: sample
+
+## Tasks
+
+- [>] Zulu task
+  @id: zulu
+- [>] Alpha task
+  @id: alpha
+",
+    );
+    let conn = lash_db::open_database(&db_path).unwrap();
+
+    let mut activity = ActivityState::default();
+    activity.seed_from_db(&conn, Instant::now());
+
+    let seeded = activity
+        .in_progress
+        .as_ref()
+        .expect("an in-progress task should have been seeded");
+    assert_eq!(
+        seeded.full_id, "sample#alpha",
+        "seeding must be deterministic on full_id, not on row order"
+    );
+}
+
+#[test]
+fn seeding_leaves_in_progress_empty_when_nothing_is_in_progress() {
+    let (_temp_dir, db_path) = setup_project(
+        r"# Sample
+
+@id: sample
+
+## Tasks
+
+- [ ] Open task
+- [x] Done task
+",
+    );
+    let conn = lash_db::open_database(&db_path).unwrap();
+
+    let mut activity = ActivityState::default();
+    activity.seed_from_db(&conn, Instant::now());
+
+    assert!(activity.in_progress.is_none());
+}
+
+/// Drive the app to the Tasks pane with the first task selected, then press
+/// Space `toggles` times. Returns the app so the caller can inspect state.
+fn app_after_toggles(db_path: &PathBuf, toggles: usize) -> lash_tui::testing::TestTuiApp {
+    // Tab twice to move focus Navigation -> Description -> Detail (the tasks
+    // pane), which is where Space toggles rather than warning.
+    let mut events = vec![keys::tab(), keys::tab()];
+    for _ in 0..toggles {
+        events.push(keys::char(' '));
+    }
+
+    let mut app = TestAppBuilder::new()
+        .with_db(db_path)
+        .with_size(80, 24)
+        .with_events(events)
+        .build()
+        .unwrap();
+
+    // One tick per queued event, plus the initial render.
+    for _ in 0..=(2 + toggles) {
+        app.tick().unwrap();
+    }
+    app
+}
+
+#[test]
+fn toggling_open_to_in_progress_fills_the_in_progress_slot() {
+    let (_temp_dir, db_path) = setup_project(
+        r"# Sample
+
+@id: sample
+
+## Tasks
+
+- [ ] Alpha task
+  @id: alpha
+",
+    );
+
+    let app = app_after_toggles(&db_path, 1);
+
+    let in_progress = app
+        .state()
+        .activity
+        .in_progress
+        .as_ref()
+        .expect("toggling Open -> InProgress should fill the in-progress slot");
+    assert_eq!(in_progress.title, "Alpha task");
+    assert!(
+        app.state().activity.recently_completed.is_empty(),
+        "nothing has completed yet"
+    );
+}
+
+#[test]
+fn toggling_in_progress_to_done_clears_the_slot_and_records_the_completion() {
+    let (_temp_dir, db_path) = setup_project(
+        r"# Sample
+
+@id: sample
+
+## Tasks
+
+- [ ] Alpha task
+  @id: alpha
+",
+    );
+
+    // Open -> InProgress -> Done.
+    let app = app_after_toggles(&db_path, 2);
+
+    assert!(
+        app.state().activity.in_progress.is_none(),
+        "completing the in-progress task must clear the slot"
+    );
+    let recent = &app.state().activity.recently_completed;
+    assert_eq!(recent.len(), 1, "the completion should have been recorded");
+    assert_eq!(recent[0].title, "Alpha task");
+}
diff --git a/tasks/tasks.md b/tasks/tasks.md
index c040756..a93b35c 100644
--- a/tasks/tasks.md
+++ b/tasks/tasks.md
@@ -44,8 +44,8 @@ Tasks are organized by major module/component. Each task file contains:
 ### User Interfaces
 - [x] [tasks.tui.md](tasks.tui.md) - Terminal UI implementation ✅
 - [x] [tasks.task-creation-ui.md](tasks.task-creation-ui.md) - Task creation via CLI (`lash add`) and TUI form modal (Tasks 1-12 complete) ✅
-- [ ] [tasks.status-bar-activity.md](tasks.status-bar-activity.md) - Status bar in-progress + recently-completed activity sections
-- [ ] [tasks.live-updates.md](tasks.live-updates.md) - Live TUI updates (Store actor, file watcher, external-change reload)
+- [x] [tasks.status-bar-activity.md](tasks.status-bar-activity.md) - Status bar in-progress + recently-completed activity sections ✅
+- [x] [tasks.live-updates.md](tasks.live-updates.md) - Live TUI updates (Store actor, file watcher, external-change reload) ✅
 
 ### Advanced Features
 - [x] [tasks.agent-integration.md](tasks.agent-integration.md) - Agent prompts, token minimization (Tasks 1-6 complete) ✅
diff --git a/tasks/tasks.status-bar-activity.md b/tasks/tasks.status-bar-activity.md
index adc2bb8..dc4015b 100644
--- a/tasks/tasks.status-bar-activity.md
+++ b/tasks/tasks.status-bar-activity.md
@@ -71,7 +71,7 @@ completion times.
 
 - [x] Seed via existing `TaskRepository::find_by_status(InProgress)` (already ordered by `full_id` — no new query needed)
 - [x] Seed `state.activity.in_progress` in `TuiApp::new_with_scheme`
-- [ ] Test: DB with two in-progress tasks → smaller full_id wins *(deferred — relies on TUI integration harness; ordering itself is covered by existing repository tests)*
+- [x] Test: DB with two in-progress tasks → smaller full_id wins *(`crates/lash-tui/tests/activity_bar_tests.rs`; the fixture lists `zulu` above `alpha` so row order and full_id order disagree)*
 
 ---
 
@@ -93,7 +93,7 @@ for its transient duration.
 - [x] Insert `record_transition` call after `update_markdown_task_status` succeeds (primary toggle path)
 - [x] Hook the three cascading handlers (`handle_confirm_cascading_complete`, `handle_confirm_linked_file_complete`, `handle_confirm_cascading_incomplete`) — initiating task only, not cascade results
 - [x] Existing tests for `handle_toggle_status` still pass
-- [ ] New end-to-end test: toggling Open→InProgress sets `activity.in_progress`; InProgress→Done clears it and pushes to recent *(deferred to Phase C when a more general TUI integration harness exists; covered indirectly by unit tests on `ActivityState::record_transition`)*
+- [x] New end-to-end test: toggling Open→InProgress sets `activity.in_progress`; InProgress→Done clears it and pushes to recent *(`crates/lash-tui/tests/activity_bar_tests.rs`, driven through `TestAppBuilder` and real Space key events)*
 
 ---