docs(files): align stale dimension docs with the overwrite/self-heal behavior

Cleanup audit: the ImageDimensionsSource/reportImageDimensions interface docs and
one route log string still said backfill-once/no-op; the mechanism overwrites on
mismatch to self-correct. Wording only, no behavior change.

Author: waleedlatif1

apps/sim/app/api/workspaces/[id]/files/[fileId]/dimensions/route.ts

@@ -46,7 +46,7 @@ export const PATCH = withRouteHandler(
       })
       return NextResponse.json({ success: written })
     } catch (error) {
-      logger.error('Failed to backfill workspace file dimensions', {
+      logger.error('Failed to store workspace file dimensions', {
         workspaceId,
         fileId,
         error: getErrorMessage(error),

apps/sim/hooks/use-file-content-source.tsx

@@ -28,13 +28,17 @@ export interface ImageDimensions {
 
 /**
  * Optional per-context capability: reserve layout space for an embedded image from its intrinsic size,
- * so it never reflows on load. The workspace source backs this with file-list metadata plus a lazy
- * backfill; public/embedded sources omit it and fall back to on-load measurement (one reflow, no persist).
+ * so it never reflows on load. The workspace source backs this with file-list metadata plus a self-
+ * correcting metadata write; public/embedded sources omit it and fall back to on-load measurement (one
+ * reflow, no persist).
  */
 export interface ImageDimensionsSource {
   /** Intrinsic dimensions for an embedded image `src` if already known — read synchronously at render. */
   getImageDimensions: (src: string | undefined) => ImageDimensions | null
-  /** Persist an image's measured intrinsic dimensions (fire-and-forget; a no-op once already stored). */
+  /**
+   * Persist an image's measured intrinsic dimensions (fire-and-forget). Overwrites a stored value that
+   * disagrees so a stale size self-corrects; a no-op only when the stored value already matches.
+   */
   reportImageDimensions: (src: string | undefined, dimensions: ImageDimensions) => void
 }