refactor(db): unwind vestigial worker source plumbing (ADR-0052 follow-up)

ADR-0052 moved success journaling out of the worker to the dispatch
layer, leaving the `source` that handlers threaded purely for the
worker's old history.log write dead. Remove it:

- drop `_source` from finalize_persistence and do_rebuild_from_text
- inline + delete the three read-only *_request wrappers
- drop the now-unused `source` param from the ~30 forwarding worker
  handlers (leaf + composite), compiler-guided
- remove the `source` field from the DescribeTable/QueryData/RunSelect
  requests and their DatabaseHandle methods (call sites updated)

The only worker `source` left is the snapshot/undo label
(snapshot_then / stage_pre_mutation / begin_batch). Purely mechanical,
no behaviour change. 2471 pass / 0 fail / 1 ignored, clippy clean.

tests/it/replay_command.rs

@@ -108,13 +108,13 @@ fn replay_runs_advanced_sql_create_table_as_a_write() {
 
     // The SQL DDL line actually created the structural table…
     let desc = rt()
-        .block_on(async { db.describe_table("Widget".to_string(), None).await })
+        .block_on(async { db.describe_table("Widget".to_string()).await })
         .expect("describe");
     let names: Vec<String> = desc.columns.iter().map(|c| c.name.clone()).collect();
     assert_eq!(names, vec!["id".to_string(), "name".to_string()]);
     // …and the following insert (serial id auto-filled) ran against it.
     let rows = rt()
-        .block_on(async { db.query_data("Widget".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("Widget".to_string(), None, None).await })
         .expect("query")
         .rows;
     assert_eq!(rows.len(), 1);
@@ -139,7 +139,7 @@ fn replay_three_lines_dispatches_three_commands() {
 
     // The dispatched commands actually mutated state.
     let data_result = rt()
-        .block_on(async { db.query_data("T".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("T".to_string(), None, None).await })
         .expect("query_data");
     assert_eq!(data_result.rows.len(), 1, "row inserted");
     assert_eq!(data_result.rows[0][1].as_deref(), Some("Alice"));
@@ -174,7 +174,7 @@ fn replay_of_actual_history_log_runs_ok_commands_and_skips_err() {
     assert_completed(&events, 3);
 
     let data_result = rt()
-        .block_on(async { db.query_data("T".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("T".to_string(), None, None).await })
         .expect("query_data");
     assert_eq!(data_result.rows.len(), 1, "only the ok INSERT applied");
     assert_eq!(data_result.rows[0][1].as_deref(), Some("alpha"));
@@ -227,7 +227,7 @@ fn replay_skips_app_lifecycle_commands_silently() {
         other => panic!("expected ReplayCompleted, got {other:?}"),
     }
     let data_result = rt()
-        .block_on(async { db.query_data("T".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("T".to_string(), None, None).await })
         .expect("query_data");
     assert!(
         data_result.columns.iter().any(|c| c == "v"),
@@ -401,14 +401,14 @@ fn replay_aborts_on_first_parse_failure_and_reports_line() {
     // but earlier commands stayed applied (table T exists with
     // the `name` column).
     let desc = rt()
-        .block_on(async { db.describe_table("T".to_string(), None).await })
+        .block_on(async { db.describe_table("T".to_string()).await })
         .expect("describe_table");
     assert!(
         desc.columns.iter().any(|c| c.name == "name"),
         "earlier add column should have stayed applied"
     );
     let data_result = rt()
-        .block_on(async { db.query_data("T".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("T".to_string(), None, None).await })
         .expect("query_data");
     assert!(
         data_result.rows.is_empty(),
@@ -467,7 +467,7 @@ fn replay_rejects_wrong_type_value_in_a_hand_built_script() {
     // The earlier two lines stayed applied; the failing insert
     // did not run — state is intact.
     let data_result = rt()
-        .block_on(async { db.query_data("T".to_string(), None, None, None).await })
+        .block_on(async { db.query_data("T".to_string(), None, None).await })
         .expect("query_data");
     assert!(
         data_result.rows.is_empty(),
@@ -527,7 +527,7 @@ fn replay_skips_nested_replay_with_a_warning() {
         other => panic!("expected ReplayCompleted (nested replay skipped), got {other:?}"),
     }
     // The nested file's table was NOT created (the replay was skipped).
-    let cols = rt().block_on(async { db.query_data("T".to_string(), None, None, None).await });
+    let cols = rt().block_on(async { db.query_data("T".to_string(), None, None).await });
     assert!(cols.is_err(), "inner.commands' table T must not exist (nested replay skipped)");
 }