fix(a11y): give clickable thumbnails, icon tiles and a pseudo-link real semantics

Three more click targets with no keyboard path.

DocumentThumbnail repeats its onClick across four render branches, so the
semantics are built once and only when a handler was actually given — a
decorative thumbnail should not take a tab stop.

The OCR setup-guide text was styled as a link and opened one, but was a
Text with an onClick: unreachable by keyboard and no target cue on hover.
It is now an anchor.

IconSelector's tiles are choices, so they say so, and each carries the
label its tooltip already showed.

Author: reecebrowne

frontend/editor/src/core/components/shared/filePreview/DocumentThumbnail.tsx

@@ -33,6 +33,23 @@ const DocumentThumbnail: React.FC<DocumentThumbnailProps> = ({
 }) => {
   if (!file) return null;
 
+  // A thumbnail that takes a click is a control; without these it is a div, so
+  // the file cannot be opened by keyboard. Only applied when a handler was
+  // given — a decorative thumbnail should not take a tab stop.
+  const interactive = onClick
+    ? {
+        role: "button",
+        tabIndex: 0,
+        onClick,
+        onKeyDown: (e: React.KeyboardEvent<HTMLElement>) => {
+          if (e.key === "Enter" || e.key === " ") {
+            e.preventDefault();
+            onClick();
+          }
+        },
+      }
+    : {};
+
   const containerStyle: React.CSSProperties = {
     position: "relative",
     cursor: onClick ? "pointer" : "default",
@@ -47,7 +64,7 @@ const DocumentThumbnail: React.FC<DocumentThumbnailProps> = ({
 
   if (thumbnail && !isEncrypted) {
     return (
-      <Box style={containerStyle} onClick={onClick}>
+      <Box style={containerStyle} {...interactive}>
         <PrivateContent>
           <img
             src={thumbnail}
@@ -77,7 +94,7 @@ const DocumentThumbnail: React.FC<DocumentThumbnailProps> = ({
 
   if (isEncrypted) {
     return (
-      <Box style={containerStyle} onClick={onClick}>
+      <Box style={containerStyle} {...interactive}>
         <div
           style={{
             display: "flex",
@@ -116,7 +133,7 @@ const DocumentThumbnail: React.FC<DocumentThumbnailProps> = ({
 
   if (isLoading) {
     return (
-      <Box style={containerStyle} onClick={onClick}>
+      <Box style={containerStyle} {...interactive}>
         <Stack
           align="center"
           justify="center"
@@ -136,7 +153,7 @@ const DocumentThumbnail: React.FC<DocumentThumbnailProps> = ({
   const ext = detectFileExtension(file.name ?? "").toUpperCase();
 
   return (
-    <Box style={containerStyle} onClick={onClick}>
+    <Box style={containerStyle} {...interactive}>
       <Center
         style={{
           width: "100%",

frontend/editor/src/core/components/tools/automate/IconSelector.tsx

@@ -92,7 +92,16 @@ export default function IconSelector({
                 return (
                   <Tooltip key={option.value} label={option.label}>
                     <Box
+                      role="button"
+                      tabIndex={0}
+                      aria-label={option.label}
                       onClick={() => handleIconSelect(option.value)}
+                      onKeyDown={(e) => {
+                        if (e.key === "Enter" || e.key === " ") {
+                          e.preventDefault();
+                          handleIconSelect(option.value);
+                        }
+                      }}
                       style={{
                         display: "flex",
                         alignItems: "center",

frontend/editor/src/core/components/tools/ocr/LanguagePicker.tsx

@@ -155,20 +155,21 @@ const LanguagePicker: React.FC<LanguagePickerProps> = ({
             "Looking for additional languages?",
           )}
         </Text>
+        {/* A real anchor: it was styled as a link and opened one, but as a
+            Text with an onClick it could not be reached by keyboard and gave
+            no target cue on hover. */}
         <Text
+          component="a"
+          href="https://docs.stirlingpdf.com/Configuration/OCR"
+          target="_blank"
+          rel="noopener noreferrer"
           size="xs"
           style={{
             color: "var(--c-accent-text)",
             cursor: "pointer",
             textDecoration: "underline",
             textAlign: "center",
           }}
-          onClick={() =>
-            window.open(
-              "https://docs.stirlingpdf.com/Configuration/OCR",
-              "_blank",
-            )
-          }
         >
           {t("ocr.languagePicker.viewSetupGuide", "View setup guide →")}
         </Text>