feat: Add OCR script for PDFs using Ollama and refine document preview navigation and zoom behavior.

frontend/src/styles/preview/preview-zoom.css

@@ -6,10 +6,12 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  z-index: 2000000;
-  cursor: zoom-out;
+  z-index: 6000000;
+  cursor: default;
   opacity: 0;
   pointer-events: none;
+  backdrop-filter: blur(8px);
+  -webkit-backdrop-filter: blur(8px);
 }
 
 .preview-zoom-backdrop--visible {
@@ -23,8 +25,9 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  z-index: 3000000;
+  z-index: 6000001;
   --preview-padding: 1.5vmin;
+  --header-clearance: calc(2.5rem + 0.5rem);
 }
 
 .preview-zoom__stage--pdf {
@@ -42,6 +45,8 @@
   display: flex;
   align-items: center;
   justify-content: center;
+  padding-top: var(--header-clearance);
+  box-sizing: border-box;
 }
 
 .preview-zoom__scroll--pdf {
@@ -60,6 +65,8 @@
 }
 
 .preview-zoom__scroll--native {
+  width: 100%;
+  height: 100%;
   overflow: auto;
   cursor: zoom-out;
   justify-content: flex-start;
@@ -73,6 +80,8 @@
   display: flex;
   justify-content: center;
   align-items: flex-start;
+  padding-top: var(--header-clearance);
+  box-sizing: border-box;
 }
 
 .preview-zoom__pdf-viewer {
@@ -93,4 +102,23 @@
   z-index: -1;
   pointer-events: none;
   border-radius: inherit;
+}
+
+/* Header positioning for preview zoom overlay */
+.preview-zoom-backdrop .panel-header--dark {
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  z-index: 6000002;
+  cursor: default;
+  backdrop-filter: blur(4px);
+  -webkit-backdrop-filter: blur(4px);
+  pointer-events: auto;
+  box-shadow: 0 1rem 0.5rem var(--shadow-subtle);
+}
+
+/* Prevent header clicks from closing backdrop */
+.preview-zoom-backdrop .panel-header--dark * {
+  pointer-events: auto;
 }