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/PHASE27-NOTES.md

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+# Phase 27 — Charts, colours, schema editor
+
+- Imports Swift Charts; adds coloured line/area charts to Administration > View Trends, based on existing in-memory samples.
+- Metric picker and coloured rates in performance counters.
+- Schema tree: right-click schema > Create Table; right-click table > Edit Table Schema.
+- Schema inspector displays SHOW FULL COLUMNS, SHOW INDEX, SHOW CREATE TABLE.
+- SQL DDL editing with confirmation; requires suitable MySQL permissions. No automatic table reconstruction.
+
+IMPORTANT: Not compiled in Xcode here. Test against a disposable MySQL database. DDL may implicitly commit.