feat(ui): migrate to Tailwind (compiled) + Flowbite JS; new navbar/layout; Docker CSS build

- Add multi-stage CSS build that compiles Tailwind into app/static/tw.css
- Add Tailwind config with dark tokens (bg/nav/card) and purge globs
- Add assets/input.css (@tailwind base/components/utilities + small utilities)
- Replace Tailwind CDN + REMOVE Flowbite CSS (keep Flowbite JS only)
- New base_tailwind.html (top navbar, responsive container, {%- block scripts -%})
- Port pages to Tailwind look/feel with wider content column:
  - index: single-column form + recent results, fullscreen spinner overlay, copy-UUID
  - result: sticky jump list, Tailwind tables/badges, Suspicious Scripts/Forms sections
  - viewer: Monaco-based code viewer in Tailwind card, actions (copy/wrap/raw)
  - ssl_tls macro: rewritten with Tailwind (details/summary for raw JSON)
- Dockerfile: add css-builder stage and copy built tw.css into /app/app/static
- Remove Flowbite stylesheet to avoid overrides; Flowbite JS loaded with defer

BREAKING CHANGE:
Legacy CSS classes/components (.card, .badge, etc.) are replaced by Tailwind utilities.
All templates now expect tw.css to be served from /static.

app/templates/viewer.html

@@ -1,25 +1,44 @@
 {% extends "base.html" %}
+{% block title %}Source Viewer{% endblock %}
+
 {% block content %}
-<div style="max-width:1100px;margin:0 auto;padding:1rem 1.25rem;">
-  <header style="display:flex;align-items:center;justify-content:space-between;gap:1rem;flex-wrap:wrap;">
-    <div>
-      <h2 style="margin:0;font-size:1.1rem;">Code Viewer</h2>
-      <div class="text-dim" style="font-size:0.9rem;">
-        <strong>File:</strong> <span id="fileName">{{ filename }}</span>
+<div class="max-w-xl md:max-w-3xl lg:max-w-5xl xl:max-w-6xl 2xl:max-w-7xl mx-auto space-y-4">
+  <section class="bg-card border border-gray-800 rounded-xl p-4">
+    <header class="flex items-center justify-between gap-3 flex-wrap">
+      <div>
+        <h2 class="text-lg font-semibold">Source Viewer</h2>
+        <div class="text-sm text-gray-400">
+          <strong>File:</strong> <span id="fileName" class="break-all">{{ filename }}</span>
+        </div>
       </div>
-    </div>
-    <div style="display:flex;gap:.5rem;align-items:center;">
-      <button id="copyBtn" class="btn btn-sm">Copy</button>
-      <button id="wrapBtn" class="btn btn-sm">Toggle wrap</button>
-      <a id="openRaw" class="btn btn-sm" href="{{ raw_url }}" target="_blank" rel="noopener">Open raw</a>
-      <a id="downloadRaw" class="btn btn-sm" href="{{ raw_url }}" download>Download</a>
-    </div>
-  </header>
+      <div class="flex items-center gap-2">
+        <button id="copyBtn"
+                class="inline-flex items-center rounded-lg px-3 py-1.5 bg-gray-800 hover:bg-gray-700 border border-gray-700 text-sm">
+          Copy
+        </button>
+        <button id="wrapBtn"
+                class="inline-flex items-center rounded-lg px-3 py-1.5 bg-gray-800 hover:bg-gray-700 border border-gray-700 text-sm">
+          Toggle wrap
+        </button>
+        <a id="openRaw" href="{{ raw_url }}" target="_blank" rel="noopener"
+           class="inline-flex items-center rounded-lg px-3 py-1.5 bg-gray-800 hover:bg-gray-700 border border-gray-700 text-sm">
+          Open raw
+        </a>
+        <a id="downloadRaw" href="{{ raw_url }}" download
+           class="inline-flex items-center rounded-lg px-3 py-1.5 bg-gray-800 hover:bg-gray-700 border border-gray-700 text-sm">
+          Download
+        </a>
+      </div>
+    </header>
 
-  <div id="viewerStatus" class="text-dim" style="margin:.5rem 0 .75rem;"></div>
-  <div id="editor" style="height:72vh;border:1px solid #1f2a36;border-radius:8px;"></div>
+    <div id="viewerStatus" class="text-sm text-gray-400 mt-2 mb-3"></div>
+
+    <div id="editor" class="h-[72vh] border border-gray-800 rounded-lg"></div>
+  </section>
 </div>
+{% endblock %}
 
+{% block scripts %}
 <!-- Monaco AMD loader (no integrity to avoid mismatch) -->
 <script src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.49.0/min/vs/loader.min.js"
         crossorigin="anonymous" referrerpolicy="no-referrer"></script>
@@ -36,13 +55,18 @@
     if (!name) return 'plaintext';
     const m = name.toLowerCase().match(/\.([a-z0-9]+)$/);
     const ext = m ? m[1] : '';
-    const map = {js:'javascript',mjs:'javascript',cjs:'javascript',ts:'typescript',json:'json',
-                 html:'html',htm:'html',css:'css',py:'python',sh:'shell',bash:'shell',
-                 yml:'yaml',yaml:'yaml',md:'markdown',txt:'plaintext',log:'plaintext'};
+    const map = {
+      js:'javascript', mjs:'javascript', cjs:'javascript',
+      ts:'typescript', json:'json',
+      html:'html', htm:'html', css:'css',
+      py:'python', sh:'shell', bash:'shell',
+      yml:'yaml', yaml:'yaml',
+      md:'markdown', txt:'plaintext', log:'plaintext'
+    };
     return map[ext] || 'plaintext';
   }
 
-  // Wait until the AMD loader has defined window.require
+  // Wait until the AMD loader defines window.require
   function waitForRequire(msLeft = 5000) {
     return new Promise((resolve, reject) => {
       const t0 = performance.now();
@@ -90,15 +114,23 @@
 
         // Buttons
         document.getElementById('copyBtn')?.addEventListener('click', async () => {
-          try { await navigator.clipboard.writeText(editor.getValue()); statusEl.textContent = 'Copied.'; }
-          catch (e) { statusEl.textContent = 'Copy failed: ' + e; }
+          try {
+            await navigator.clipboard.writeText(editor.getValue());
+            statusEl.textContent = 'Copied.';
+          } catch (e) {
+            statusEl.textContent = 'Copy failed: ' + e;
+          }
         });
+
         document.getElementById('wrapBtn')?.addEventListener('click', () => {
           const opts = editor.getRawOptions();
           editor.updateOptions({ wordWrap: opts.wordWrap === 'on' ? 'off' : 'on' });
         });
 
-        statusEl.textContent = (resp.ok ? '' : `Warning: HTTP ${resp.status}`) + (text.length ? '' : ' (empty file)');
+        // Status
+        const warn = resp.ok ? '' : `Warning: HTTP ${resp.status}`;
+        const empty = text.length ? '' : (warn ? ' · empty file' : 'Empty file');
+        statusEl.textContent = warn + (warn && empty ? '' : '') + (empty || '');
       });
     } catch (err) {
       statusEl.textContent = 'Viewer error: ' + err.message;