feat(05-02): printer detail page with export buttons and command preview

- Update printer_detail() to pass install_cmd, uninstall_cmd, has_driver, has_icon to template
- Rewrite printer_detail.html with Intune Commands, Export, and Icon sections
- Show command strings with Alpine.js copy-to-clipboard buttons (install-cmd, uninstall-cmd)
- Show NinjaRMM ZIP and .intunewin download links when driver assigned
- Add HTMX icon upload form with #icon-status swap target
- Remove disabled placeholder Regenerate Package button
- Add TestCommandPreview class (4 tests) to test_packages.py
- All 94 tests pass

imptune/templates/printer_detail.html

@@ -24,10 +24,44 @@
   <p>No driver assigned</p>
   {% endif %}
 
-  <h2>Actions</h2>
-  <button disabled aria-busy="false" title="Available after script generation is implemented (Phase 4)">
-    Regenerate Package
-  </button>
+  {% if has_driver %}
+  <h2>Intune Commands</h2>
+  <div x-data="{ copiedInstall: false }">
+    <label>Install command</label>
+    <code id="install-cmd">{{ install_cmd }}</code>
+    <button @click="
+      const text = document.getElementById('install-cmd').innerText;
+      navigator.clipboard.writeText(text).then(() => { copiedInstall = true; setTimeout(() => copiedInstall = false, 2000) })
+      .catch(() => { /* fallback: text is visible for manual copy */ })
+    " x-text="copiedInstall ? 'Copied!' : 'Copy'" class="secondary outline"></button>
+  </div>
+  <div x-data="{ copiedUninstall: false }">
+    <label>Uninstall command</label>
+    <code id="uninstall-cmd">{{ uninstall_cmd }}</code>
+    <button @click="
+      const text = document.getElementById('uninstall-cmd').innerText;
+      navigator.clipboard.writeText(text).then(() => { copiedUninstall = true; setTimeout(() => copiedUninstall = false, 2000) })
+      .catch(() => { /* fallback: text is visible for manual copy */ })
+    " x-text="copiedUninstall ? 'Copied!' : 'Uninstall copy'" class="secondary outline"></button>
+  </div>
+
+  <h2>Export</h2>
+  <a href="/printers/{{ printer.id }}/packages/ninja" role="button">Download NinjaRMM ZIP</a>
+  <a href="/printers/{{ printer.id }}/packages/intunewin" role="button">Download .intunewin</a>
+  {% endif %}
+
+  <h2>Icon</h2>
+  {% if has_icon %}
+  <p>Icon uploaded</p>
+  {% endif %}
+  <form hx-post="/printers/{{ printer.id }}/icon"
+        hx-target="#icon-status" hx-swap="innerHTML"
+        enctype="multipart/form-data">
+    <input type="file" name="file" accept="image/png" required>
+    <button type="submit">Upload Icon</button>
+  </form>
+  <div id="icon-status"></div>
+
   <a href="/printers" role="button" class="secondary">Back to Printers</a>
 </article>
 {% endblock %}