Add dedicated edition pages (server, workstation, cloud)

- Add /server, /workstation, /cloud routes with per-page SEO titles
- Extract shared nav, footer, and waitlist form into partials
- Nav links to edition pages with active-state highlighting; swap About/Security order
- Waitlist form pre-checks the current edition and adds a Cloud option
- Add page-hero variant, edition switcher, and active-nav styles
- Responsive fixes: nav wraps at 540px, waitlist checkboxes wrap on narrow screens

templates/partials/waitlist_form.html

@@ -0,0 +1,34 @@
+{{define "waitlistForm"}}
+<form
+    hx-post="/partials/waitlist"
+    hx-target="#waitlist-result"
+    hx-swap="outerHTML"
+    class="waitlist-form"
+>
+    <fieldset class="edition-checkboxes">
+        <legend>I'm interested in:</legend>
+        <label class="edition-checkbox">
+            <input type="checkbox" name="edition" value="server"{{if eq .Edition "server"}} checked{{end}}>
+            <span>Server</span>
+        </label>
+        <label class="edition-checkbox">
+            <input type="checkbox" name="edition" value="workstation"{{if eq .Edition "workstation"}} checked{{end}}>
+            <span>Workstation</span>
+        </label>
+        <label class="edition-checkbox">
+            <input type="checkbox" name="edition" value="cloud"{{if eq .Edition "cloud"}} checked{{end}}>
+            <span>Cloud</span>
+        </label>
+    </fieldset>
+    <input
+        type="email"
+        name="email"
+        placeholder="you@example.com"
+        required
+        class="input"
+    >
+    <button type="submit" class="btn">Get Early Access</button>
+</form>
+<div id="waitlist-result"></div>
+<p class="waitlist-note">No spam. No tracking. We'll only email you when there's something to try.</p>
+{{end}}