Copy polish + sideload link fix

- Hero lede rewritten to lead with what Keysat is (a self-hosted
  licensing server) and what buyers do, dropping the
  empowers/monetize SaaS-speak.
- Sovereignty subhead consolidates the BTCPay + key-holding lines
  into one sentence focused on ownership.
- Card 01 (install) drops the BTCPay-bundled aside.
- Card 05 (share URL) rewritten to not over-emphasize Bitcoin
  ("pay for your software" + "verified offline").
- Sideload link now points at files.keysat.xyz directly. The prior
  github.com/keysat-xyz/keysat/releases URL was 404 (no releases on
  the private repo). Once the repo flips to public + has releases,
  this can revert to the GitHub URL.

index.html

@@ -570,7 +570,7 @@ footer.site .bottom a { color:rgba(245,241,232,0.6); }
       <div class="eyebrow">Software licensing for independent creators</div>
       <h1>Self-hosted licensing for software creators.</h1>
       <p class="lede">
-        Keysat empowers software creators to monetize their work. Keysat is fully self-hosted and is Bitcoin-native. Your software verifies signed keys offline. You own the signing key, the customer list, and the payment rails &mdash; no SaaS, no middleman, no platform risk.
+        Keysat is a self-hosted licensing server. Buyers pay you for the software you create, and their license can be verified offline. Your licensing key, customer list, and payment rails all live on your hardware &mdash; no SaaS, no middleman, no platform risk.
       </p>
       <div class="cta-row">
         <a class="btn primary lg" href="#install">Install Keysat <span class="arrow">&rarr;</span></a>
@@ -616,7 +616,7 @@ footer.site .bottom a { color:rgba(245,241,232,0.6); }
     <div class="section-head">
       <span class="eyebrow">What this enables</span>
       <h2>A complete sell-your-software stack, sovereign end-to-end.</h2>
-      <p>Keysat is the licensing layer. BTCPay handles payments. Your hardware holds the keys. No third party can mint, revoke, or read your sales records.</p>
+      <p>Keysat is the licensing layer. Your hardware holds the keys and controls payment rails. No third party can mint, revoke, or read your sales records.</p>
     </div>
     <div class="value-grid">
       <div class="item">
@@ -764,11 +764,11 @@ footer.site .bottom a { color:rgba(245,241,232,0.6); }
       <p>From install to first sale in an afternoon. No cloud account to create, no API keys to copy.</p>
     </div>
     <ol class="flow">
-      <li class="step"><div class="num">01</div><h3>Install on your Start9</h3><p>One click from <code>registry.keysat.xyz</code> in the StartOS marketplace. BTCPay comes bundled as a dependency. (Sideload the <code>.s9pk</code> directly if you prefer.)</p></li>
+      <li class="step"><div class="num">01</div><h3>Install on your Start9</h3><p>One click from <code>registry.keysat.xyz</code> in the StartOS marketplace. (Sideload the <code>.s9pk</code> directly if you prefer.)</p></li>
       <li class="step"><div class="num">02</div><h3>Connect BTCPay</h3><p>One click in the StartOS Actions tab. Authorize once on BTCPay's consent page; Keysat registers a webhook automatically.</p></li>
       <li class="step"><div class="num">03</div><h3>Define products + policies</h3><p>Declare a product, set its price in sats, define a policy (duration, seat cap, trial, entitlements).</p></li>
       <li class="step"><div class="num">04</div><h3>Embed your public key</h3><p>Copy your Keysat public key into your app. Add the SDK. Five lines of code verifies a signature at startup.</p></li>
-      <li class="step"><div class="num">05</div><h3>Share your purchase URL</h3><p>Buyers hit your public URL, pay in Bitcoin, get a signed license. Their copy of your software boots up licensed.</p></li>
+      <li class="step"><div class="num">05</div><h3>Share your purchase URL</h3><p>Buyers hit your public URL, pay for your software, and get a signed license that can be verified offline.</p></li>
     </ol>
   </div>
 </section>
@@ -969,7 +969,7 @@ fmt.<span class="f">Printf</span>(<span class="s">"licensed for %s, expires %s\n
         <h3>Sideload</h3>
         <p>If you'd rather not add the marketplace:</p>
         <ol>
-          <li>Download <code>keysat_x86_64.s9pk</code> from <a href="https://github.com/keysat-xyz/keysat/releases">GitHub releases</a>.</li>
+          <li>Download <a href="https://files.keysat.xyz/keysat_x86_64.s9pk"><code>keysat_x86_64.s9pk</code></a>.</li>
           <li>StartOS dashboard &rarr; Sideload &rarr; drag the file in.</li>
           <li>Click Install.</li>
         </ol>