fix: Add data transformer to resolve metrics dashboard template mismatch

Root cause: Template expects flat structure (metrics.database.count) but
monitoring module provides nested structure (metrics.by_type.database.count)
with different field names (avg_duration_ms vs avg).

Solution: Route Adapter Pattern - transformer function maps data structure
at presentation layer.

Changes:
- Add transform_metrics_for_template() function to admin.py
- Update metrics_dashboard() route to use transformer
- Provide safe defaults for missing/empty metrics data
- Handle all operation types: database, http, render

Testing: All 32 admin route tests passing

Documentation:
- Updated implementation report with actual fix details
- Created consolidated hotfix design documentation
- Architectural review by architect (approved with minor concerns)

Technical debt: Adapter layer should be replaced with proper data
contracts in v1.2.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

starpunk/routes/admin.py

@@ -215,6 +215,51 @@ def delete_note_submit(note_id: int):
     return redirect(url_for("admin.dashboard"))
 
 
+def transform_metrics_for_template(metrics_stats):
+    """
+    Transform metrics stats to match template structure
+
+    The template expects direct access to metrics.database.count, but
+    get_metrics_stats() returns metrics.by_type.database.count.
+    This function adapts the data structure to match template expectations.
+
+    Args:
+        metrics_stats: Dict from get_metrics_stats() with nested by_type structure
+
+    Returns:
+        Dict with flattened structure matching template expectations
+
+    Per ADR-060: Route Adapter Pattern for template compatibility
+    """
+    transformed = {}
+
+    # Map by_type to direct access
+    for op_type in ['database', 'http', 'render']:
+        if 'by_type' in metrics_stats and op_type in metrics_stats['by_type']:
+            type_data = metrics_stats['by_type'][op_type]
+            transformed[op_type] = {
+                'count': type_data.get('count', 0),
+                'avg': type_data.get('avg_duration_ms', 0),
+                'min': type_data.get('min_duration_ms', 0),
+                'max': type_data.get('max_duration_ms', 0)
+            }
+        else:
+            # Provide defaults for missing types or when by_type doesn't exist
+            transformed[op_type] = {
+                'count': 0,
+                'avg': 0,
+                'min': 0,
+                'max': 0
+            }
+
+    # Keep other top-level stats
+    transformed['total_count'] = metrics_stats.get('total_count', 0)
+    transformed['max_size'] = metrics_stats.get('max_size', 1000)
+    transformed['process_id'] = metrics_stats.get('process_id', 0)
+
+    return transformed
+
+
 @bp.route("/metrics-dashboard")
 @require_auth
 def metrics_dashboard():
@@ -254,9 +299,19 @@ def metrics_dashboard():
     pool_stats = {}
 
     try:
-        metrics_data = get_metrics_stats()
+        raw_metrics = get_metrics_stats()
+        metrics_data = transform_metrics_for_template(raw_metrics)
     except Exception as e:
         flash(f"Error loading metrics: {e}", "warning")
+        # Provide safe defaults matching template expectations
+        metrics_data = {
+            'database': {'count': 0, 'avg': 0, 'min': 0, 'max': 0},
+            'http': {'count': 0, 'avg': 0, 'min': 0, 'max': 0},
+            'render': {'count': 0, 'avg': 0, 'min': 0, 'max': 0},
+            'total_count': 0,
+            'max_size': 1000,
+            'process_id': 0
+        }
 
     try:
         pool_stats = get_pool_stats()