feat: redesign page heroes, implement organic markers, and streamline contact flow

- Refined hero sections for About, Blog, Websites, and Case Studies for a bespoke industrial entry point.
- Redesigned Marker component using layered SVG paths for an organic, hand-drawn highlighter effect.
- Restored technical precision in ArchitectureVisualizer with refined line thickness.
- Streamlined contact page by removing generic headers and prioritizing the configurator/gateway.
- Updated technical references to reflect self-hosted Gitea infrastructure.
- Cleaned up unused imports and addressed linting warnings across modified pages.

apps/web/src/lib/env.ts

@@ -0,0 +1,20 @@
+import { z } from "zod";
+import { validateMintelEnv } from "@mintel/next-utils";
+
+/**
+ * Environment variable schema extension.
+ */
+const envExtension = {
+  // Mail Configuration
+  MAIL_HOST: z.string().optional(),
+  MAIL_PORT: z.coerce.number().optional().default(587),
+  MAIL_USER: z.string().optional(),
+  MAIL_PASS: z.string().optional(),
+  MAIL_FROM: z.string().optional().default("marc@mintel.me"),
+  MAIL_RECIPIENTS: z.string().optional().default("marc@mintel.me"),
+};
+
+/**
+ * Validated environment object.
+ */
+export const env = validateMintelEnv(envExtension);