feat: rework runtime charts and fix time range propagation

Runtime page (AgentInstance):
- Rearrange charts: CPU, Memory, GC (top); Threads, Chunks Exported,
  Chunks Dropped (bottom). Removes throughput/error charts (belong on
  Dashboard, not Runtime).
- Pass global time range (from/to) to useAgentMetrics — charts now
  respect the time filter instead of always showing last 60 minutes.
- Bottom row (logs + timeline) fills remaining vertical space.

Dashboard L3:
- Processor metrics section fills remaining vertical space.
- Chart x-axis uses timestamps instead of bucket indices.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/DashboardTab/DashboardL3.tsx

@@ -383,7 +383,7 @@ export default function DashboardL3() {
       )}
 
       {/* Processor Metrics — toggle between diagram and table */}
-      <div className={tableStyles.tableSection}>
+      <div className={`${tableStyles.tableSection} ${styles.processorSection}`}>
         <div className={tableStyles.tableHeader}>
           <span className={tableStyles.tableTitle}>Processor Metrics</span>
           <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>

ui/src/pages/DashboardTab/DashboardTab.module.css

@@ -42,9 +42,18 @@
   text-decoration: underline;
 }
 
-/* Diagram container — height override; card styling via tableStyles.tableSection */
+/* Processor section — fills remaining vertical space */
+.processorSection {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  min-height: 0;
+}
+
+/* Diagram container — fills remaining space inside processor section */
 .diagramHeight {
-  height: 280px;
+  flex: 1;
+  min-height: 280px;
 }
 
 /* Chart fill */