feat: enhance error handling with PostHog integration

- Added PostHog error capturing for non-authentication errors in BaseApiService.
- Refactored PostHog client initialization to ensure a single instance is used across the application.

surfsense_web/lib/apis/base-api.service.ts

@@ -1,3 +1,4 @@
+import posthog from "posthog-js";
 import type { ZodType } from "zod";
 import { getBearerToken, handleUnauthorized, refreshAccessToken } from "../auth-utils";
 import { AppError, AuthenticationError, AuthorizationError, NotFoundError } from "../error";
@@ -231,6 +232,20 @@ class BaseApiService {
 			return data;
 		} catch (error) {
 			console.error("Request failed:", JSON.stringify(error));
+			if (!(error instanceof AuthenticationError)) {
+				try {
+					posthog.captureException(error, {
+						api_url: url,
+						api_method: options?.method ?? "GET",
+						...(error instanceof AppError && {
+							status_code: error.status,
+							status_text: error.statusText,
+						}),
+					});
+				} catch {
+					// PostHog capture failed — don't block the error flow
+				}
+			}
 			throw error;
 		}
 	}