fix: CRITICAL - Do not re-sort rows by NodeNum after MySQL ORDER BY consolidation key

Bug: After fetching rows ordered by consolidation key (UnitName, ToolNameID,
EventDate, EventTime) from MySQL, code was re-sorting by NodeNum. This breaks
the grouping because rows with different consolidation keys get intermixed.

Example of what was happening:
- MySQL returns: (Unit1, Tool1, Date1, Time1, Node1),
                 (Unit1, Tool1, Date1, Time1, Node12),
                 (Unit2, Tool2, Date2, Time2, Node1)
- Re-sorting by NodeNum gives: (Unit1, Tool1, Date1, Time1, Node1),
                               (Unit2, Tool2, Date2, Time2, Node1),
                               (Unit1, Tool1, Date1, Time1, Node12)
- Result: Different consolidation keys are now mixed, each node becomes separate group!

Fix: Remove the re-sort. Trust MySQL's ORDER BY to keep rows of same key together.
The clustering nature of InnoDB ensures rows with same consolidation key are
physically adjacent.

This was causing 1 row per node instead of consolidating all nodes of same
measurement into 1 row.

🤖 Generated with Claude Code

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/connectors/mysql_connector.py

@@ -275,16 +275,16 @@ class MySQLConnector:
                         if not rows:
                             return
 
-                        # Sort rows by NodeNum within the batch
+                        # DO NOT re-sort by NodeNum! The database has already ordered by consolidation key,
-                        # (rows already grouped by consolidation key from ORDER BY)
+                        # and re-sorting breaks the grouping. Rows with same key will not be consecutive anymore.
-                        sorted_rows = sorted(rows, key=lambda r: int(r.get("NodeNum") or 0))
+                        # We trust the MySQL ORDER BY to keep all rows of same key together.
 
                         # Group rows by consolidation key
-                        # Since rows are already ordered by key, all rows with same key are consecutive
+                        # Since rows are already ordered by key from MySQL ORDER BY, all rows with same key are consecutive
                         current_group = []
                         current_key = None
 
-                        for row in sorted_rows:
+                        for row in rows:
                             key = (
                                 row.get("UnitName"),
                                 row.get("ToolNameID"),