Add per-instance mod management with client-side detection

- New mod validation engine (src/mods.rs) with constant-pool class-file
  scanning: detects server-side content (block, tileentity, command,
  worldgen) vs client-only API (gui, renderer, forge/client)
- 7 client-only mods correctly detected (AppleSkin, CraftingTweaks,
  Durability101, EnchantmentDescriptions, InventoryHUD, MouseTweaks,
  TrashSlot); 51 server-capable; 1 unknown
- Routes + templating for mod upload (jar/zip), listing, delete, rescan
- Multipart upload with 500MB limit (bypasses axum's default 2MB)
- Per-instance mod summary card on edit page
- Whitelist toggle checkbox on edit page (persisted, drives ENABLE_WHITELIST)
- Dynamic Java image tag (java8/java17/java21) based on MC version
- Class scan is informational-only; rejection based on metadata side=CLIENT
- has_modpack flag cleanup on mod delete
- Remove hx-boost from <body> (was corrupting multipart uploads)

1 files changed, 24 insertions, 26 deletions

diff --git a/templates/base.html b/templates/base.html
index 3a92cd0..0af5d57 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -1,37 +1,35 @@
-<!DOCTYPE html>
+<!doctype html>
 <html lang="en">
-<head>
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>Minecraft UI</title>
     <script src="/static/htmx.min.js"></script>
-    <link rel="stylesheet" href="/static/style.css">
-</head>
-<body hx-boost="true">
-    <nav>
-        <span class="brand">Minecraft UI</span>
-        <div class="nav-links">
-            <a href="/">Dashboard</a>
-            <a href="/instances">Instances</a>
-            <a href="/players">Players</a>
-            {% if is_superuser %}
-            <a href="/accounts">Accounts</a>
-            {% endif %}
-            <span class="nav-user">{{ username }}</span>
-            <form action="/logout" method="post" style="display:inline">
-                <button type="submit" class="btn-link">Logout</button>
-            </form>
-        </div>
+    <link rel="stylesheet" href="/static/style.css" />
+  </head>
+  <body>
+    <nav hx-boost="true">
+      <span class="brand">Minecraft UI</span>
+      <div class="nav-links">
+        <a href="/">Dashboard</a>
+        <a href="/instances">Instances</a>
+        <a href="/players">Players</a>
+        {% if is_superuser %}
+        <a href="/accounts">Accounts</a>
+        {% endif %}
+        <span class="nav-user">{{ username }}</span>
+        <form action="/logout" method="post" style="display: inline">
+          <button type="submit" class="btn-link">Logout</button>
+        </form>
+      </div>
     </nav>
 
     {% if password_change_required %}
     <div class="flash flash-warn">
-        You must change your password before continuing.
+      You must change your password before continuing.
     </div>
     {% endif %}
 
-    <main>
-        {% block content %}{% endblock %}
-    </main>
-</body>
+    <main>{% block content %}{% endblock %}</main>
+  </body>
 </html>