test(tui): align image and idle layout fixtures with validated behavior

Use the shared valid PNG for extension-independent image detection and assert that truncated PNG input retains an omission receipt. Keep the ambient-floor boundary test while accounting for the model identity row requested before the first message.

Validation: formatting and diff checks passed. npm test passed 66 wrapper, 9 SDK and 446 web tests; check:web passed with 0 errors and 2 existing warnings. Prior clean-head Rust sweep passed 1527 core tests and 15353 workspace tests, with these two fixture failures and 21 skips. Corrected Rust assertions are pending the full sweep at this branch checkpoint; no release-readiness claim.

Author: CodeWhale Bot

crates/tui/src/tools/file/tests.rs

@@ -282,9 +282,14 @@ async fn contract_read_uses_magic_not_extension_for_images() {
     std::fs::write(temporary.path().join("plain.png"), "ordinary text").expect("text fixture");
     std::fs::write(
         temporary.path().join("renamed.data"),
-        [b"\x89PNG\r\n\x1a\n".as_slice(), b"\0\0\0\rIHDR".as_slice()].concat(),
+        crate::image_attach::tests::PNG_1X1,
     )
     .expect("image fixture");
+    std::fs::write(
+        temporary.path().join("truncated.png"),
+        [b"\x89PNG\r\n\x1a\n".as_slice(), b"\0\0\0\rIHDR".as_slice()].concat(),
+    )
+    .expect("truncated image fixture");
     let context = ToolContext::new(temporary.path());
 
     let text = ReadFileTool::execute_contract_read(json!({"path": "plain.png"}), &context)
@@ -300,6 +305,11 @@ async fn contract_read_uses_magic_not_extension_for_images() {
         codewhale_tools::ToolResultContentBlock::Image { mime_type, .. }
             if mime_type == "image/png"
     ));
+    let truncated = ReadFileTool::execute_contract_read(json!({"path": "truncated.png"}), &context)
+        .await
+        .expect("invalid image retains an omission receipt");
+    assert!(truncated.content_blocks.is_empty());
+    assert!(truncated.content.contains("Image omitted"));
 }
 
 #[test]

crates/tui/src/tui/ui/tests.rs

@@ -25855,32 +25855,32 @@ mod work_surface {
             );
         }
 
-        // 20 rows seats the ocean floor exactly: the fully idle shell hides
-        // its metrics row (footer 1 + composer floor 3 + ambient floor 16).
-        // 19 rows
+        // 21 rows seats the ocean floor exactly: the idle shell keeps model
+        // identity visible (model 1 + footer 1 + composer 3 + ambient 16).
+        // 20 rows
         // cannot seat the ocean at any strip height. That is pre-rail
         // behavior and the yield rule must not pretend otherwise.
         let mut app = busy_rail_app(panel);
         assert_eq!(
-            strip_height(&mut app, 80, 20),
+            strip_height(&mut app, 80, 21),
             0,
-            "80x20 seats the ocean floor but has no spare rows for a strip"
+            "80x21 seats the ocean floor but has no spare rows for a strip"
         );
-        let rendered = render_underwater_test_app(&mut app, 80, 20);
+        let rendered = render_underwater_test_app(&mut app, 80, 21);
         assert!(
             idle_ocean_visible(&app),
-            "80x20 is exactly the ocean floor under the idle shell:\n{rendered}"
+            "80x21 is exactly the ocean floor under the idle shell:\n{rendered}"
         );
         let mut app = busy_rail_app(panel);
         assert_eq!(
-            strip_height(&mut app, 80, 19),
+            strip_height(&mut app, 80, 20),
             0,
-            "80x19 has no spare rows for a strip at all"
+            "80x20 has no spare rows for a strip at all"
         );
-        let rendered = render_underwater_test_app(&mut app, 80, 19);
+        let rendered = render_underwater_test_app(&mut app, 80, 20);
         assert!(
             !idle_ocean_visible(&app),
-            "80x19 has no room for the ocean even with no strip at all\n{rendered}"
+            "80x20 has no room for the ocean even with no strip at all\n{rendered}"
         );
     }