refactor(file-upload): SSR-first state, click-to-replace, cleaner preview

- Server renders initial file-upload state (src, alt, label text,
  has-current class) so there is no flash of broken-image icon while
  JS boots. JS no longer duplicates that work — it only reacts to
  user input (select, clear, drag-and-drop) and uses data-current-src
  solely to restore the server file after a blob preview.
- Clicking the current preview image now opens the file dialog, mirrors
  the Replace button, with hover affordance (cursor + primary border).
- Drop the transparency checker pattern in the preview — the admin UI
  does not need Figma-style transparency semantics. Preview is now a
  flat theme-aware surface (--app-preview-bg) that keeps white or
  black logos visible against a neutral gray.
- Move tenant favicon out of the aside into the Master-data tab as its
  own details block next to the Tenant-logos section. Uses the same
  barrier-form pattern (HTML5 form attribute + app-file-upload.phtml)
  for a consistent instant-upload UX.
- Tenant-logo slot label is a native <label> element — picks up the
  global form-label typography and spacing, no custom muted-color
  class needed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/css/components/app-file-upload.css

@@ -32,15 +32,15 @@
     object-fit: contain;
     object-position: center;
     border: 1px solid var(--app-muted-border-color);
-    background-color: var(--app-preview-checker-bg);
-    background-image:
-      linear-gradient(45deg, var(--app-preview-checker-fg) 25%, transparent 25%),
-      linear-gradient(-45deg, var(--app-preview-checker-fg) 25%, transparent 25%),
-      linear-gradient(45deg, transparent 75%, var(--app-preview-checker-fg) 75%),
-      linear-gradient(-45deg, transparent 75%, var(--app-preview-checker-fg) 75%);
-    background-size: 16px 16px;
-    background-position: 0 0, 0 8px, 8px -8px, -8px 0;
+    background-color: var(--app-preview-bg);
     box-sizing: border-box;
+    cursor: pointer;
+    transition: border-color 0.15s ease, opacity 0.15s ease;
+  }
+
+  .app-file-upload-current-image:hover {
+    border-color: var(--app-primary);
+    opacity: 0.92;
   }
 
   .app-file-upload-current-meta {
@@ -189,14 +189,7 @@
     object-fit: contain;
     object-position: center;
     border: 1px solid var(--app-muted-border-color);
-    background-color: var(--app-preview-checker-bg);
-    background-image:
-      linear-gradient(45deg, var(--app-preview-checker-fg) 25%, transparent 25%),
-      linear-gradient(-45deg, var(--app-preview-checker-fg) 25%, transparent 25%),
-      linear-gradient(45deg, transparent 75%, var(--app-preview-checker-fg) 75%),
-      linear-gradient(-45deg, transparent 75%, var(--app-preview-checker-fg) 75%);
-    background-size: 16px 16px;
-    background-position: 0 0, 0 8px, 8px -8px, -8px 0;
+    background-color: var(--app-preview-bg);
     box-sizing: border-box;
   }
 

web/css/components/app-tenant-logo.css

@@ -18,20 +18,15 @@
     max-height: calc(var(--app-topbar-height) - 1rem);
   }
 
-  /* Tenant-edit "Tenant logos" slots — two Pico .grid columns. */
+  /* Tenant-edit "Tenant logos" slots — two Pico .grid columns.
+     The slot's <label> uses the standard form-label rule (block,
+     margin-bottom, --app-color, text-sm) so it matches other inputs. */
   .tenant-logo-slot {
     display: flex;
     flex-direction: column;
-    gap: 0.5rem;
     min-width: 0;
   }
 
-  .tenant-logo-slot-label {
-    font-size: var(--text-sm);
-    color: var(--app-muted-color);
-    margin: 0;
-  }
-
   .tenant-logo-actions {
     display: flex;
     justify-content: flex-end;