♻️ Restructure: Move Astro to repository root

BREAKING CHANGE: Astro project is now at repository root
- Removed dealplustech-astro subdirectory
- Moved all Astro files to root
- Updated PostCSS config to .cjs
- Removed old Next.js files

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✅ Ready for Easypanel deployment (no root dir needed)

Migration path:
- Old structure: /dealplustech-astro/
- New structure: / (root)

dealplustech-astro/node_modules/unified/lib/callable-instance.js

@@ -1,44 +0,0 @@
-export const CallableInstance =
-  /**
-   * @type {new <Parameters extends Array<unknown>, Result>(property: string | symbol) => (...parameters: Parameters) => Result}
-   */
-  (
-    /** @type {unknown} */
-    (
-      /**
-       * @this {Function}
-       * @param {string | symbol} property
-       * @returns {(...parameters: Array<unknown>) => unknown}
-       */
-      function (property) {
-        const self = this
-        const constr = self.constructor
-        const proto = /** @type {Record<string | symbol, Function>} */ (
-          // Prototypes do exist.
-          // type-coverage:ignore-next-line
-          constr.prototype
-        )
-        const value = proto[property]
-        /** @type {(...parameters: Array<unknown>) => unknown} */
-        const apply = function () {
-          return value.apply(apply, arguments)
-        }
-
-        Object.setPrototypeOf(apply, proto)
-
-        // Not needed for us in `unified`: we only call this on the `copy`
-        // function,
-        // and we don't need to add its fields (`length`, `name`)
-        // over.
-        // See also: GH-246.
-        // const names = Object.getOwnPropertyNames(value)
-        //
-        // for (const p of names) {
-        //   const descriptor = Object.getOwnPropertyDescriptor(value, p)
-        //   if (descriptor) Object.defineProperty(apply, p, descriptor)
-        // }
-
-        return apply
-      }
-    )
-  )