Merge branch 'maintenance-page'

Adds dynamic maintenance page served by nginx during deploys, toggled
via a flag file by scripts/deploy-remote.sh. Includes brand-styled
maintenance.html with Goodwalk logo and contact fallback, plus an
env-template merger and a11y polish.

src/lib/components/ServicesSection.svelte

@@ -25,7 +25,9 @@
           {/if}
 
           {#if service.href}
-            <a href={service.href} class="btn btn-green">Learn more</a>
+            <a href={service.href} class="btn btn-green">
+              Learn more<span class="visually-hidden"> about {service.title}</span>
+            </a>
           {/if}
         </div>
       {/each}

src/lib/styles/base.css

@@ -34,3 +34,15 @@ input,
 textarea {
   font: inherit;
 }
+
+.visually-hidden {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}