Show a preview for images too large for the browser to display (BL-16597)

PAPERCUTS.md

@@ -116,6 +116,29 @@ House rules:
   the exit code" hazard, different cause.
 
 
+## 2026-07-27 — Three C# tests fail intermittently under load
+
+- **Cut:** `CheckAudioForAllText_SpansAudioMissing`, `BringBookUpToDate_MovesMetaDataToJson` and
+  `InsertPageAfter_FromAnotherBook_CopiesWidget(True)` fail sometimes and pass sometimes. They
+  failed together on one full-suite run, passed on a second run at the *identical* commit, and
+  passed when run on their own — so they are flaky rather than broken, and none of them is anywhere
+  near what that branch was changing (image handling). The cost is that a full run can no longer be
+  trusted on one reading: an agent has to run the suite twice to tell noise from a real regression.
+  That matters more now than when this was first written, because the full suite otherwise comes
+  back completely green (see the 2026-08-04 note below) — these three are the only remaining noise,
+  so any other failure is signal.
+- **Idea:** Find the shared state (all three build books/collections in temp folders, so likely a
+  fixture or folder-name collision when the suite runs under load) — or, cheaply, quarantine them
+  with `[Retry]` so the noise stops masking real failures.
+- **Context:** BloomDesktop, seen during `/preflight` of PR #8111 (BL-16597), on two of six
+  full-suite runs that day.
+- **2026-08-04:** All three passed on a full run of 3027 tests with **0 failures** — the first
+  entirely green full suite under `build/agent-dotnet.sh`, now that PR #8107 has fixed the nine
+  environmental failures that used to accompany them. Not evidence against this cut: intermittent
+  is intermittent. Recorded because it removes the nine-failure baseline the original wording
+  leaned on.
+
+
 ## 2026-07-24 — agent-dotnet.sh test exits 0 even when tests fail
 
 - **Cut:** `build/agent-dotnet.sh test src/BloomTests/BloomTests.csproj` returned exit code 0 on a

src/BloomBrowserUI/react_components/image-gallery/ImageGalleryDialog.tsx

@@ -101,16 +101,24 @@ const ImageGalleryDialog: React.FunctionComponent<{
             {},
         );
         if (!response) return undefined;
-        const { filePath, previewUrl } = response.data as {
+        const { filePath, previewUrl, width, height, size } = response.data as {
             filePath: string;
             previewUrl: string;
+            width: number;
+            height: number;
+            size: number;
         };
         if (!filePath) return undefined;
         return {
             thumbnailUrl: previewUrl,
             reasonableSizeUrl: previewUrl,
             localPath: filePath,
-            size: 0,
+            // C# reports the original file's dimensions and byte count. These matter because
+            // previewUrl may serve a downscaled stand-in for an image too large for the
+            // browser to display, and we want to report what the user actually chose.
+            width: width || undefined,
+            height: height || undefined,
+            size: size ?? 0,
             type: "image",
         };
     };