Improved progress display

Previously, the progress bar updated only after completing an entire table.

For large tables such as LIBARC, this could make the application appear to have stopped responding.

Phase 10 updates the interface while rows are being exported.

docs/PHASE23-NOTES.md

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+# Phase 23 — Query Plan History and Comparison
+
+Adds locally saved EXPLAIN snapshots (Table or JSON), history scoped to the same connection name, database, and SQL statement, baseline comparison, and deletion. Table-plan comparison includes a sum of optimizer-estimated rows across steps, not measured execution times. Snapshots are stored in UserDefaults (max 40, max encoded size 2 MB).
+
+The existing EXPLAIN inspector and query plan observations remain unchanged. No SQL statements are executed beyond EXPLAIN.
+
+**Validation:** Source changes and archive structure inspected; no macOS/Xcode build or live MySQL tests performed.