feat: add interactive Chart.js trend chart and improve KPI card layout

- Replace static SVG trend chart with Chart.js bar+line mixed chart

- Click-triggered custom tooltip popup with per-day detail overlay

- KPI cards: flex column layout, compact K/M currency formatting

- Custom legend above chart for consistent spacing

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

package.json

@@ -10,9 +10,14 @@
     "preview": "vite preview --host 127.0.0.1"
   },
   "dependencies": {
+    "@primevue/themes": "^4.5.4",
     "@vitejs/plugin-vue": "^5.2.4",
     "@vueuse/motion": "^3.0.3",
+    "chart.js": "^4.5.1",
+    "primeicons": "^7.0.0",
+    "primevue": "^4.5.5",
     "vite": "^5.4.19",
-    "vue": "^3.5.13"
+    "vue": "^3.5.13",
+    "vue-chartjs": "^5.3.3"
   }
 }