chore: remove Electric SQL plumbing and infrastructure

Remove all Electric SQL client code, Docker service, env vars, CI build
args, install scripts, and documentation. Feature hooks that depend on
Electric are intentionally left in place to be rewritten with Rocicorp
Zero in subsequent commits.

Deleted:
- lib/electric/ (client.ts, context.ts, auth.ts, baseline.ts)
- ElectricProvider.tsx
- docker/scripts/init-electric-user.sh
- content/docs/how-to/electric-sql.mdx

Cleaned:
- package.json (4 @electric-sql/* deps)
- app/layout.tsx, UserDropdown.tsx, LayoutDataProvider.tsx
- docker-compose.yml, docker-compose.dev.yml
- Dockerfile, docker-entrypoint.js
- .env.example (frontend, docker, backend)
- CI workflows, install scripts, docs

surfsense_web/components/providers/ElectricProvider.tsx

@@ -1,116 +0,0 @@
-"use client";
-
-import { useAtomValue } from "jotai";
-import { usePathname } from "next/navigation";
-import { useEffect, useRef, useState } from "react";
-import { currentUserAtom } from "@/atoms/user/user-query.atoms";
-import { useGlobalLoadingEffect } from "@/hooks/use-global-loading";
-import { getBearerToken } from "@/lib/auth-utils";
-import {
-	cleanupElectric,
-	type ElectricClient,
-	initElectric,
-	isElectricInitialized,
-} from "@/lib/electric/client";
-import { ElectricContext } from "@/lib/electric/context";
-
-interface ElectricProviderProps {
-	children: React.ReactNode;
-}
-
-/**
- * Initializes user-specific PGlite database with Electric SQL sync.
- * Handles user isolation, cleanup, and re-initialization on user change.
- */
-export function ElectricProvider({ children }: ElectricProviderProps) {
-	const [electricClient, setElectricClient] = useState<ElectricClient | null>(null);
-	const [error, setError] = useState<Error | null>(null);
-	const {
-		data: user,
-		isSuccess: isUserLoaded,
-		isError: isUserError,
-	} = useAtomValue(currentUserAtom);
-	const previousUserIdRef = useRef<string | null>(null);
-	const initializingRef = useRef(false);
-	const pathname = usePathname();
-
-	useEffect(() => {
-		if (typeof window === "undefined") return;
-
-		// No user logged in - cleanup if previous user existed
-		if (!isUserLoaded || !user?.id) {
-			if (previousUserIdRef.current && isElectricInitialized()) {
-				console.log("[ElectricProvider] User logged out, cleaning up...");
-				cleanupElectric().then(() => {
-					previousUserIdRef.current = null;
-					setElectricClient(null);
-				});
-			}
-			return;
-		}
-
-		const userId = String(user.id);
-
-		// Skip if already initialized for this user or currently initializing
-		if ((electricClient && previousUserIdRef.current === userId) || initializingRef.current) {
-			return;
-		}
-
-		initializingRef.current = true;
-		let mounted = true;
-
-		async function init() {
-			try {
-				console.log(`[ElectricProvider] Initializing for user: ${userId}`);
-				const client = await initElectric(userId);
-
-				if (mounted) {
-					previousUserIdRef.current = userId;
-					setElectricClient(client);
-					setError(null);
-					console.log(`[ElectricProvider] ✅ Ready for user: ${userId}`);
-				}
-			} catch (err) {
-				console.error("[ElectricProvider] Failed to initialize:", err);
-				if (mounted) {
-					setError(err instanceof Error ? err : new Error("Failed to initialize Electric SQL"));
-					setElectricClient(null);
-				}
-			} finally {
-				if (mounted) {
-					initializingRef.current = false;
-				}
-			}
-		}
-
-		init();
-		return () => {
-			mounted = false;
-		};
-	}, [user?.id, isUserLoaded, electricClient]);
-
-	const hasToken = typeof window !== "undefined" && !!getBearerToken();
-
-	// Only block UI on dashboard routes; public pages render immediately
-	const requiresElectricLoading = pathname?.startsWith("/dashboard");
-	const shouldShowLoading =
-		hasToken && isUserLoaded && !!user?.id && !electricClient && !error && requiresElectricLoading;
-
-	useGlobalLoadingEffect(shouldShowLoading);
-
-	// Render immediately for unauthenticated users or failed user queries
-	if (!hasToken || !isUserLoaded || !user?.id || isUserError) {
-		return <ElectricContext.Provider value={null}>{children}</ElectricContext.Provider>;
-	}
-
-	// Render with null context while initializing
-	if (!electricClient && !error) {
-		return <ElectricContext.Provider value={null}>{children}</ElectricContext.Provider>;
-	}
-
-	if (error) {
-		console.warn("[ElectricProvider] Initialization failed, sync may not work:", error.message);
-	}
-
-	return <ElectricContext.Provider value={electricClient}>{children}</ElectricContext.Provider>;
-}