fix: workspace panel close button — no duplicate X on desktop, mobile X respects file preview (#414)

* fix: workspace panel close button — no duplicate X on desktop, mobile X respects file preview

Two bugs fixed in the workspace right panel:

1. Duplicate X on desktop (bug): #btnClearPreview (the X icon) was always
   visible alongside #btnCollapseWorkspacePanel (the chevron), producing two
   close controls at once. Fixed in syncWorkspacePanelUI() — on desktop, the X
   is now hidden when no file preview is open (display:none), and only shown
   when the user is viewing a file. The chevron remains as the sole close
   control in browse mode.

2. Mobile X collapses panel instead of dismissing file (bug): .mobile-close-btn
   was calling closeWorkspacePanel() directly, which collapsed the whole panel
   even when a file was open. Changed to handleWorkspaceClose(), which already
   has the correct two-step logic: clear preview first, close panel only if
   no preview is visible.

Files changed:
- static/boot.js: syncWorkspacePanelUI() hides btnClearPreview on desktop
  when hasPreview is false, guarded by !isCompact so mobile is unaffected
- static/index.html: mobile-close-btn onclick changed from
  closeWorkspacePanel() to handleWorkspaceClose()
- tests/test_sprint44.py: 10 new regression tests
- tests/test_mobile_layout.py: updated test_workspace_close_button_present()
  to accept handleWorkspaceClose() as the valid onclick target

* fix: widen test_server_delete_invalidates_index window to 1200 chars

The test extracted a 600-char window starting from the session/delete
handler to check for SESSION_INDEX_FILE. Commit 3cc5839 added session_id
character validation and path traversal guards before the unlink call,
pushing SESSION_INDEX_FILE to ~764 chars from the match — beyond the
600-char limit, causing the test to fail on CI.

Widened the window to 1200 chars, which accommodates any reasonable
amount of guard code before the SESSION_INDEX_FILE.unlink() call.

* docs: v0.50.33 release — version badge and CHANGELOG

---------

Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>

static/boot.js

@@ -118,6 +118,10 @@ function syncWorkspacePanelUI(){
   if(clearBtn){
     clearBtn.disabled=!isOpen;
     clearBtn.title=hasPreview?'Close preview':'Hide workspace panel';
+    // On desktop, only show the X button when a file preview is open.
+    // In browse mode the chevron (btnCollapseWorkspacePanel) already serves
+    // as the close control, so showing both produces a duplicate X.
+    if(!isCompact) clearBtn.style.display=hasPreview?'':'none';
   }
 }
 

static/index.html

@@ -358,7 +358,7 @@
         <button class="panel-icon-btn" id="btnNewFolder" title="New folder" onclick="promptNewFolder()"><svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z"/></svg></button>
         <button class="panel-icon-btn" id="btnRefreshPanel" title="Refresh" onclick="if(S.session)loadDir(S.currentDir)"><svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><polyline points="23 4 23 10 17 10"/><polyline points="1 20 1 14 7 14"/><path d="M3.51 9a9 9 0 0 1 14.85-3.36L23 10M1 14l4.64 4.36A9 9 0 0 0 20.49 15"/></svg></button>
         <button class="panel-icon-btn close-preview" id="btnClearPreview" title="Close preview"><svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/></svg></button>
-        <button class="panel-icon-btn mobile-close-btn" onclick="closeWorkspacePanel()" title="Close" aria-label="Close workspace panel">×</button>
+        <button class="panel-icon-btn mobile-close-btn" onclick="handleWorkspaceClose()" title="Close" aria-label="Close workspace panel">×</button>
       </div>
     </div>
     <div class="breadcrumb-bar" id="breadcrumbBar" style="display:none"></div>
@@ -535,7 +535,7 @@
                 <div class="settings-section-title">System</div>
                 <div class="settings-section-meta">Instance version and access controls.</div>
               </div>
-              <span class="settings-version-badge">v0.50.32</span>
+              <span class="settings-version-badge">v0.50.33</span>
             </div>
             <div class="settings-field" style="border-top:1px solid var(--border);padding-top:12px;margin-top:8px">
               <label for="settingsPassword" data-i18n="settings_label_password">Access Password</label>