feat: add async tour system

Players can create tours with selected courses/layouts and a date range.
Others join via a 6-character tour code, play the courses, and report
their total strokes. Live leaderboard with points and +/- par display.

Includes: database schema, model, service, routes, views, and styling.

views/partials/nav.ejs

@@ -1,4 +1,5 @@
 <nav class="app-nav">
     <a href="/" class="<%= activePage === 'players' ? 'active' : '' %>">Players</a>
     <a href="/courses" class="<%= activePage === 'courses' ? 'active' : '' %>">Courses</a>
+    <a href="/tours" class="<%= activePage === 'tours' ? 'active' : '' %>">Tours</a>
 </nav>

views/partials/tour-leaderboard.ejs

@@ -0,0 +1,52 @@
+<% if (leaderboard.length === 0) { %>
+  <div class="card-section">
+    <p style="text-align: center; color: var(--text-secondary);">No players have joined yet. Share the tour link to get started!</p>
+  </div>
+<% } else { %>
+  <div class="card-section">
+    <h3>Leaderboard</h3>
+    <table>
+      <thead>
+        <tr>
+          <th>#</th>
+          <th>Player</th>
+          <% courses.forEach(function(c) { %>
+            <th class="mobile-hide"><%= c.course_name %><br><small><%= c.layout_name %></small></th>
+          <% }); %>
+          <th>Points</th>
+        </tr>
+      </thead>
+      <tbody>
+        <% var rank = 1; %>
+        <% leaderboard.forEach(function(player, i) { %>
+          <% if (i > 0 && player.total_points < leaderboard[i-1].total_points) rank = i + 1; %>
+          <tr>
+            <td><strong><%= rank %></strong></td>
+            <td>
+              <%= player.player_name %>
+              <span style="color: var(--text-muted); font-size: 12px;"><%= player.pdga_number %></span>
+            </td>
+            <% courses.forEach(function(c) { %>
+              <td class="mobile-hide">
+                <% var result = player.courses[c.tour_course_id]; %>
+                <% if (result) { %>
+                  <span class="strokes"><%= result.total_strokes %></span>
+                  <% if (result.relative_par > 0) { %>
+                    <span class="over-par">(+<%= result.relative_par %>)</span>
+                  <% } else if (result.relative_par < 0) { %>
+                    <span class="under-par">(<%= result.relative_par %>)</span>
+                  <% } else { %>
+                    <span class="even-par">(E)</span>
+                  <% } %>
+                <% } else { %>
+                  <span style="color: var(--text-muted);">-</span>
+                <% } %>
+              </td>
+            <% }); %>
+            <td><strong><%= player.total_points %></strong></td>
+          </tr>
+        <% }); %>
+      </tbody>
+    </table>
+  </div>
+<% } %>