feat(web): glow-pulse on primary CTAs + hero fills full first viewport

Two coordinated polish moves:

1. **<PulseLink> / <PulseButton>** — new `apps/web/components/pulse.tsx`.
   Click anywhere on a wrapped link or button and a small indigo dot
   detonates from the click point, scaling 1x→80x over 650ms before
   fading to transparent. Same visual language as the hero load-in
   glow — the click effectively says "this is the brand reaching back."

   The dot lives in a `pointer-events: none` overlay, so it never
   blocks the underlying navigation. `overflow-hidden + relative` are
   added to the host so the bloom stays inside the rounded shape.
   `glow-pulse` keyframe sits in globals.css next to the existing
   `pulse-dot` / `shimmer` / `fade-in` definitions; reduced-motion
   suppresses the animation to instant-opacity-0 so the click flow
   is preserved without the bloom.

   Wired into the highest-conversion CTAs only — the user explicitly
   asked "wo's Sinn macht":
   - Hero "Start building free" + "Read the docs"
   - Marketing header Login / Dashboard button
   - Dashboard header "+ New server" pill

   Deliberately NOT applied to dashboard nav links, logout, destructive
   buttons, form internals, carousel dots — pulse on every click would
   be noise.

2. **Hero fills 100svh − nav** (`min-height: calc(100svh - 3rem)`).
   `svh` (small viewport height) instead of `vh` so the hero doesn't
   jump when the mobile address bar hides/shows. The 3rem subtracts
   the sticky marketing nav (h-12 = 48px), so the hero ends right at
   the loadscreen's natural bottom edge.

   `flex items-center` plus the inner grid's existing `md:items-center`
   keep the content vertically centred inside the tall section. The
   ParticleHero background now has cinematic-scale room and the indigo
   radial-glow + dot-mask read as the dominant background motif —
   which is the effect the user loved at load-in.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/components/marketing-auth-buttons.tsx

@@ -1,7 +1,7 @@
 'use client';
 
+import { PulseLink } from '@/components/pulse';
 import { apiFetch } from '@/lib/api';
-import Link from 'next/link';
 import { useEffect, useState } from 'react';
 
 /**
@@ -26,11 +26,11 @@ export function MarketingAuthButtons() {
   const showDashboard = authed === true;
 
   return (
-    <Link
+    <PulseLink
       href={showDashboard ? '/dashboard' : '/login'}
       className="rounded-md bg-[--color-accent] px-3 py-1.5 text-[13px] font-medium text-white transition-colors duration-200 hover:bg-[#5557e8]"
     >
       {showDashboard ? 'Dashboard' : 'Login'}
-    </Link>
+    </PulseLink>
   );
 }