Add route diagram page with execution overlay and group-aware APIs

Backend: Add group filtering to agent list, search, stats, and timeseries
endpoints. Add diagram lookup by group+routeId. Resolve application group
to agent IDs server-side for ClickHouse IN-clause queries.

Frontend: New route detail page at /apps/{group}/routes/{routeId} with
three tabs (Diagram, Performance, Processor Tree). SVG diagram rendering
with panzoom, execution overlay (glow effects, duration/sequence badges,
flow particles, minimap), and processor detail panel. uPlot charts for
performance tab replacing old SVG sparklines. Ctrl+Click from
ExecutionExplorer navigates to route diagram with overlay.

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

ui/package.json

@@ -14,9 +14,11 @@
   "dependencies": {
     "@tanstack/react-query": "^5.90.21",
     "openapi-fetch": "^0.17.0",
+    "panzoom": "^9.4.3",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
     "react-router": "^7.13.1",
+    "uplot": "^1.6.32",
     "zustand": "^5.0.11"
   },
   "devDependencies": {