feat(03-02): implement printer detail page with driver info and regenerate placeholder

- Add GET /printers/{printer_id} route to pages.py with LEFT OUTER JOINs on Client and Driver
- Create printer_detail.html full-page template showing all config fields and driver info
- Display "No driver assigned" when driver FK is null
- Add disabled "Regenerate Package" button (Phase 4 placeholder)
- Make printer names in printer_list.html clickable links to detail page

imptune/templates/partials/printer_list.html

@@ -22,7 +22,7 @@
       <tbody>
         {% for p in printers %}
         <tr>
-          <td>{{ p.name }}</td>
+          <td><a href="/printers/{{ p.id }}">{{ p.name }}</a></td>
           <td>{{ p.ip_address }}</td>
           <td>{{ p.port_name }}</td>
           <td>{{ p.driver.original_filename if p.driver_id else '—' }}</td>

imptune/templates/printer_detail.html

@@ -0,0 +1,33 @@
+{% extends "base.html" %}
+{% block content %}
+<h1>{{ printer.name }}</h1>
+<article>
+  <h2>Configuration</h2>
+  <dl>
+    <dt>IP Address</dt><dd>{{ printer.ip_address }}</dd>
+    <dt>Port Name</dt><dd>{{ printer.port_name }}</dd>
+    <dt>Duplex Mode</dt><dd>{{ printer.duplex_mode }}</dd>
+    <dt>Color Mode</dt><dd>{{ "Color" if printer.color_mode else "Grayscale" }}</dd>
+    <dt>Paper Size</dt><dd>{{ printer.paper_size }}</dd>
+    <dt>Collate</dt><dd>{{ "Yes" if printer.collate else "No" }}</dd>
+    <dt>Client</dt><dd>{{ printer.client.name if printer.client_id else "Unassigned" }}</dd>
+  </dl>
+
+  <h2>Driver</h2>
+  {% if printer.driver_id %}
+  <dl>
+    <dt>Package</dt><dd>{{ printer.driver.original_filename }}</dd>
+    <dt>Driver Name(s)</dt><dd>{{ driver_names | join(", ") }}</dd>
+    <dt>Architecture</dt><dd>{{ printer.driver.architecture or "Unknown" }}</dd>
+  </dl>
+  {% else %}
+  <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>
+  <a href="/printers" role="button" class="secondary">Back to Printers</a>
+</article>
+{% endblock %}