feat: Enhance provider components with detailed documentation and comments

- Added comprehensive comments and JSDoc-style documentation to NotificationProvider, ThemeProvider, UserProvider, and WebsiteThemeProvider for better clarity and maintainability.
- Improved type definitions in index.ts for better code understanding and usage.
- Introduced Docker support with Dockerfiles for various services including AI server, signaling server, and browser-use service.
- Created a docker-compose.yml file to orchestrate multiple services including PostgreSQL, AI, scraper, and frontend.
- Added a startup guide (startup.txt) for setting up the CRM environment on Ubuntu with Docker.
- Included a .dockerignore file to exclude unnecessary files from Docker builds.

src/app/api/settings/website-theme/route.ts

@@ -1,12 +1,23 @@
+// ── Settings: Website Theme ──────────────────────────────────────────────────
+// GET /api/settings/website-theme  — Get the current user's theme preference
+// PUT /api/settings/website-theme  — Update theme preference (stored in JSONB)
+//
+// Auth: authenticated
+// Reads and writes the website_theme and color_theme keys inside the user's
+// preferences JSONB column, preserving other preference data.
+
 import { NextRequest, NextResponse } from "next/server"
 import { getSessionUser } from "@/lib/auth"
 import { query } from "@/lib/db"
 
+// ── GET ──────────────────────────────────────────────────────────────────────
+
 export async function GET() {
   try {
     const user = await getSessionUser()
     if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
 
+    // Extract website_theme and color_theme from the JSONB preferences column
     const result = await query(
       `SELECT preferences->>'website_theme' AS website_theme, preferences->>'color_theme' AS color_theme FROM users WHERE id = $1`,
       [user.id],
@@ -21,6 +32,8 @@ export async function GET() {
   }
 }
 
+// ── PUT ──────────────────────────────────────────────────────────────────────
+
 export async function PUT(request: NextRequest) {
   try {
     const user = await getSessionUser()
@@ -35,6 +48,7 @@ export async function PUT(request: NextRequest) {
       update.color_theme = body.colorTheme || "default"
     }
 
+    // Merge into the existing JSONB preferences using || operator
     if (Object.keys(update).length > 0) {
       await query(
         `UPDATE users SET preferences = preferences || $2::jsonb WHERE id = $1`,
@@ -42,6 +56,7 @@ export async function PUT(request: NextRequest) {
       )
     }
 
+    // Return the updated values
     const result = await query(
       `SELECT preferences->>'website_theme' AS website_theme, preferences->>'color_theme' AS color_theme FROM users WHERE id = $1`,
       [user.id],