Widen the IWP screen and add a left work-package navigator

The Work Package form was capped at a 1000px column, which wasted most of a
desktop screen, and the only way to reach another package was to scroll to the
Saved table at the bottom.

- Put the form in a wide two-column shell (max 1760px); ctx-bar, mode-wrap and
  the release banner widened to match.
- Above 1200px the two-up field grids flow to 3-4 columns instead of stretching
  two fields across the whole card. Narrow layouts are unchanged.
- New sticky left rail listing every saved package, grouped by status in field
  order, with WP number, subject, readiness dot and type. Click to open it in
  the form; the package being edited is highlighted. Filter box, + New and
  Dashboard shortcuts, collapsible (state persisted), hidden under 1100px where
  the Saved table still covers navigation.
- The rail re-renders from renderSavedList(), so saves, deletes, splits,
  archive/restore and the project pull all keep it current.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

html/wp-creation-index.html

@@ -45,6 +45,23 @@
 <!-- SECTION NAV (jump links, built from the form cards) -->
 <div class="section-nav-bar" id="section-nav"></div>
 
+<div class="wp-layout">
+
+<!-- WP NAVIGATOR (left rail — jump between every work package on this project) -->
+<aside class="wp-nav" id="wp-nav" aria-label="Work packages">
+  <div class="wp-nav-head">
+    <div class="wp-nav-title">Work Packages <span class="wp-nav-count" id="wp-nav-count"></span></div>
+    <button class="wp-nav-collapse" id="wp-nav-collapse" onclick="toggleWpNav()" title="Collapse list" aria-label="Collapse list">‹</button>
+  </div>
+  <input type="search" class="wp-nav-search" id="wp-nav-search" placeholder="Filter by number, subject, type…" oninput="renderWpNav()">
+  <div class="wp-nav-list" id="wp-nav-list"></div>
+  <div class="wp-nav-foot">
+    <button class="add-btn" onclick="newPackage()">+ New</button>
+    <button class="add-btn" onclick="showDashboard()">📊 Dashboard</button>
+  </div>
+</aside>
+<button class="wp-nav-reopen" id="wp-nav-reopen" onclick="toggleWpNav()" title="Show work packages" aria-label="Show work packages">›</button>
+
 <div class="main">
 
   <!-- PACKAGE KIND (only shown when the project's SOP includes BIM/VDC) -->
@@ -268,6 +285,7 @@
   </div>
 
 </div>
+</div>
 
 <!-- HOLD LOG MODAL (comment 7) -->
 <div class="modal-overlay" id="hold-modal">