fix: only log FILE_DOWNLOADED for actual downloads, not preview URLs

getDownloadUrl was logging FILE_DOWNLOADED on every call including
inline previews and thumbnail loads. Now only logs when forDownload
is true (explicit download button click), massively reducing noise.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/routers/file.ts

@@ -124,16 +124,18 @@ export const fileRouter = router({
         })
       }
 
-      // Log file access
-      await logAudit({
-        prisma: ctx.prisma,
-        userId: ctx.user.id,
-        action: 'FILE_DOWNLOADED',
-        entityType: 'ProjectFile',
-        detailsJson: { bucket: input.bucket, objectKey: input.objectKey },
-        ipAddress: ctx.ip,
-        userAgent: ctx.userAgent,
-      })
+      // Only log actual downloads, not preview/view URL requests
+      if (input.forDownload) {
+        await logAudit({
+          prisma: ctx.prisma,
+          userId: ctx.user.id,
+          action: 'FILE_DOWNLOADED',
+          entityType: 'ProjectFile',
+          detailsJson: { bucket: input.bucket, objectKey: input.objectKey, fileName: input.fileName },
+          ipAddress: ctx.ip,
+          userAgent: ctx.userAgent,
+        })
+      }
 
       return { url }
     }),