feat(dolt): auto-commit write commands and set explicit commit authors (#1267)

* /{cmd,docs,internal}: autocommit writes in dolt backend

Executed-By: beads/crew/emma
Rig: beads
Role: crew

* /{cmd,internal}: fix commit author

Executed-By: beads/crew/emma
Rig: beads
Role: crew

* /cmd/bd: fix race condition

Executed-By: beads/crew/emma
Rig: beads
Role: crew

---------

Co-authored-by: Test <test@example.com>

cmd/bd/import.go

@@ -407,8 +407,7 @@ NOTE: Import requires direct database access and does not work with daemon mode.
 			fmt.Fprintf(os.Stderr, "\nAll text and dependency references have been updated.\n")
 		}
 
-		// Mark this command as having performed a write if it changed anything.
-		// This enables Dolt auto-commit in PersistentPostRun.
+		// Record that this command performed a write (for Dolt auto-commit).
 		if result.Created > 0 || result.Updated > 0 || len(result.IDMapping) > 0 {
 			commandDidWrite.Store(true)
 		}