feat(history): mode-tagged history + top-of-chain journaling (#30)

Record the submission mode per history entry so advanced commands are
reusable in simple mode, and fix the bug where a ':'-one-shot command
lost its ':' across sessions (ADR-0052, closing #30).

Format: the history.log status token gains an optional ':adv' suffix
(ok / ok:adv / err / err:adv); 'source' stays last and canonical, so
replay is unaffected. The in-memory ring (still Vec<String>) stores
advanced entries ': '-prefixed; recall strips the ':' in advanced mode
and keeps it in simple; hydration reconstructs the prefix from the tag.

Journaling moved from the worker to the dispatch layer (spawn_dsl_-
dispatch / run_replay / app-command sites), where the mode is in scope
with no worker plumbing; finalize_persistence writes only yaml/csv
(commit-db-last still atomic for state). The journal write is now
best-effort (command already committed), consistent with the failure
path. App commands journal simple, so they recall bare. Journaling is
now uniform (every successful command, per ADR-0034) — closing a gap
where show tables/relationships/explain didn't journal.

Amends ADR-0034 (status tag + journaling location), ADR-0015 §6
(history.log out of the worker tx), ADR-0040 (journal-write best-effort).
15 worker-level journaling tests retired, re-covered at the new layer
(history.rs format, app.rs recall matrix, iteration6 cross-session
regression, replay). 2471 pass / 0 fail / 0 skip, clippy clean.

tests/it/iteration2_persistence.rs

@@ -15,7 +15,7 @@ use rdbms_playground::db::Database;
 use rdbms_playground::dsl::{ColumnSpec, ReferentialAction, RowFilter, Type, Value};
 use rdbms_playground::persistence::Persistence;
 use rdbms_playground::project::{
-    self, DATA_DIR, HISTORY_LOG, PROJECT_YAML,
+    self, DATA_DIR, PROJECT_YAML,
 };
 
 fn tempdir() -> tempfile::TempDir {
@@ -44,11 +44,6 @@ fn open_project(
     (project, db, path)
 }
 
-fn read_history(project_path: &Path) -> Vec<String> {
-    let body = fs::read_to_string(project_path.join(HISTORY_LOG)).unwrap_or_default();
-    body.lines().map(str::to_string).collect()
-}
-
 fn read_yaml(project_path: &Path) -> String {
     fs::read_to_string(project_path.join(PROJECT_YAML)).expect("project.yaml")
 }
@@ -82,9 +77,9 @@ fn create_table_writes_yaml_and_history() {
     assert!(yaml.contains("type: serial"), "yaml: {yaml}");
     assert!(yaml.contains("type: text"), "yaml: {yaml}");
 
-    let history = read_history(&path);
-    assert_eq!(history.len(), 1, "expected one history line; got {history:?}");
-    assert!(history[0].ends_with("|ok|create table Customers with pk id(serial)"));
+    // ADR-0052: journaling moved to the dispatch layer (the worker no
+    // longer writes history.log); this test verifies only the yaml state.
+    // Journaling is covered by the history.rs/app.rs/replay tests.
 }
 
 #[test]
@@ -119,11 +114,8 @@ fn insert_writes_csv_and_history() {
     assert_eq!(lines[0], "id,Name");
     assert_eq!(lines[1], "1,Alice");
 
-    let history = read_history(&path);
-    assert!(
-        history.iter().any(|l| l.ends_with("|ok|insert into Customers ('Alice')")),
-        "history missing insert: {history:?}",
-    );
+    // ADR-0052: journaling moved off the worker; this test verifies the
+    // csv state only (journaling covered elsewhere).
 }
 
 #[test]
@@ -322,39 +314,6 @@ fn delete_all_rows_removes_csv() {
     );
 }
 
-#[test]
-fn show_table_appends_history_only() {
-    let data = tempdir();
-    let (_p, db, path) = open_project(&data);
-
-    rt().block_on(async {
-        db.create_table(
-            "Customers".to_string(),
-            vec![ColumnSpec::new("id".to_string(), Type::Serial)],
-            vec!["id".to_string()],
-            Some("create table Customers with pk id(serial)".to_string()),
-        )
-        .await
-        .unwrap();
-        let yaml_before = read_yaml(&path);
-        db.describe_table(
-            "Customers".to_string(),
-            Some("show table Customers".to_string()),
-        )
-        .await
-        .unwrap();
-        let yaml_after = read_yaml(&path);
-        // YAML body did not change for a read-only command.
-        assert_eq!(yaml_before, yaml_after);
-    });
-
-    let history = read_history(&path);
-    assert!(
-        history.iter().any(|l| l.ends_with("|ok|show table Customers")),
-        "history missing show entry: {history:?}",
-    );
-}
-
 #[test]
 fn failed_command_does_not_append_history_or_change_yaml() {
     let data = tempdir();
@@ -387,13 +346,8 @@ fn failed_command_does_not_append_history_or_change_yaml() {
         assert_eq!(yaml_before, yaml_after, "failed cmd must not change yaml");
     });
 
-    let history = read_history(&path);
-    // Only the first (successful) create_table should have logged.
-    let create_count = history
-        .iter()
-        .filter(|l| l.contains("|ok|create table Customers"))
-        .count();
-    assert_eq!(create_count, 1, "expected exactly one logged create; got: {history:?}");
+    // ADR-0052: journaling moved off the worker; this test now verifies
+    // only that a failed command does not change the yaml state.
 }
 
 #[test]