Add YAML-driven report generation

reports.yml

@@ -0,0 +1,21 @@
+- name: hits
+  interval: hourly
+  label: Hits
+  chart: bar
+  query: |
+    SELECT strftime('%Y-%m-%d %H:00:00', datetime(time)) AS bucket,
+           COUNT(*) AS value
+    FROM logs
+    GROUP BY bucket
+    ORDER BY bucket
+
+- name: error_rate
+  interval: hourly
+  label: Error Rate (%)
+  chart: line
+  query: |
+    SELECT strftime('%Y-%m-%d %H:00:00', datetime(time)) AS bucket,
+           SUM(CASE WHEN status >= 500 THEN 1 ELSE 0 END) * 100.0 / COUNT(*) AS value
+    FROM logs
+    GROUP BY bucket
+    ORDER BY bucket