feat(dashboard): optimize dashboard layout and add new charts

app/repositories/proxy_repo.py

@@ -526,3 +526,73 @@ class ProxyRepository:
         except Exception as e:
             logger.error(f"clean_expired failed: {e}", exc_info=True)
             return 0
+
+    @staticmethod
+    async def get_latency_distribution(db: aiosqlite.Connection) -> dict:
+        """获取延迟分布数据（仅已验证可用的代理）"""
+        try:
+            async with db.execute(
+                """
+                SELECT response_time_ms FROM proxies
+                WHERE validated = 1 AND score > 0 AND response_time_ms IS NOT NULL AND response_time_ms > 0
+                """
+            ) as cursor:
+                rows = await cursor.fetchall()
+                if not rows:
+                    return {"ranges": [], "counts": []}
+
+                latencies = [row[0] for row in rows]
+                ranges = ["<500ms", "500-1s", "1-2s", "2-3s", ">3s"]
+                counts = [0, 0, 0, 0, 0]
+
+                for lat in latencies:
+                    if lat < 500:
+                        counts[0] += 1
+                    elif lat < 1000:
+                        counts[1] += 1
+                    elif lat < 2000:
+                        counts[2] += 1
+                    elif lat < 3000:
+                        counts[3] += 1
+                    else:
+                        counts[4] += 1
+
+                return {"ranges": ranges, "counts": counts}
+        except Exception as e:
+            logger.error(f"get_latency_distribution failed: {e}", exc_info=True)
+            return {"ranges": [], "counts": []}
+
+    @staticmethod
+    async def get_score_distribution(db: aiosqlite.Connection) -> dict:
+        """获取评分分布数据（仅已验证可用的代理）"""
+        try:
+            async with db.execute(
+                """
+                SELECT score FROM proxies
+                WHERE validated = 1 AND score > 0
+                """
+            ) as cursor:
+                rows = await cursor.fetchall()
+                if not rows:
+                    return {"ranges": [], "counts": []}
+
+                scores = [row[0] for row in rows]
+                ranges = ["80-100", "60-80", "40-60", "20-40", "0-20"]
+                counts = [0, 0, 0, 0, 0]
+
+                for score in scores:
+                    if score >= 80:
+                        counts[0] += 1
+                    elif score >= 60:
+                        counts[1] += 1
+                    elif score >= 40:
+                        counts[2] += 1
+                    elif score >= 20:
+                        counts[3] += 1
+                    else:
+                        counts[4] += 1
+
+                return {"ranges": ranges, "counts": counts}
+        except Exception as e:
+            logger.error(f"get_score_distribution failed: {e}", exc_info=True)
+            return {"ranges": [], "counts": []}