fix(tui): preserve WezTerm Kitty images on full redraw

Reserve visible Kitty image rows before drawing placements in full redraws, while preserving the first-row path for taller-than-viewport images so #4415 stays fixed.

Closes #5618.

packages/tui/test/tui-render.test.ts

@@ -152,6 +152,95 @@ describe("TUI Kitty image cleanup", () => {
 		}
 	});
 
+	it("reserves Kitty image rows before drawing during full redraw fallbacks", async () => {
+		setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });
+		setCellDimensions({ widthPx: 10, heightPx: 10 });
+		try {
+			const terminal = new LoggingVirtualTerminal(40, 5);
+			const tui = new TUI(terminal);
+			const component = new TestComponent();
+			tui.addChild(component);
+
+			component.lines = ["l0", "l1", "l2", "l3", "l4"];
+			tui.start();
+			await terminal.waitForRender();
+			const redrawsBeforeImage = tui.fullRedraws;
+			terminal.clearWrites();
+
+			const image = new Image(
+				"AAAA",
+				"image/png",
+				{ fallbackColor: (value) => value },
+				{ maxWidthCells: 3 },
+				{ widthPx: 30, heightPx: 30 },
+			);
+			const imageLines = image.render(40);
+			const imageSequence = imageLines[0];
+			component.lines = ["l0", "l1", "l2", "l3", "l4", ...imageLines, "after"];
+			tui.requestRender();
+			await terminal.waitForRender();
+
+			const writes = terminal.getWrites();
+			assert.ok(tui.fullRedraws > redrawsBeforeImage, "scrolling image append should force a full redraw");
+			assert.ok(
+				writes.includes(`\r\n\r\n\x1b[2A${imageSequence}\x1b[2B`),
+				"full redraw should reserve visible image rows before drawing the placement",
+			);
+			assert.ok(
+				!writes.includes(`${imageSequence}\r\n\x1b[0m`),
+				"full redraw must not write reserved padding rows after drawing the placement",
+			);
+
+			tui.stop();
+		} finally {
+			resetCapabilitiesCache();
+			setCellDimensions({ widthPx: 9, heightPx: 18 });
+		}
+	});
+
+	it("does not use cursor-up placement for Kitty images taller than the viewport", async () => {
+		setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });
+		setCellDimensions({ widthPx: 10, heightPx: 10 });
+		try {
+			const terminal = new LoggingVirtualTerminal(40, 5);
+			const tui = new TUI(terminal);
+			const component = new TestComponent();
+			tui.addChild(component);
+
+			component.lines = ["before"];
+			tui.start();
+			await terminal.waitForRender();
+			terminal.clearWrites();
+
+			const image = new Image(
+				"AAAA",
+				"image/png",
+				{ fallbackColor: (value) => value },
+				{ maxWidthCells: 6 },
+				{ widthPx: 60, heightPx: 60 },
+			);
+			const imageLines = image.render(40);
+			const imageSequence = imageLines[0];
+			assert.ok(imageLines.length > terminal.rows, "test image should exceed the viewport height");
+
+			component.lines = ["before", ...imageLines, "after"];
+			tui.requestRender(true);
+			await terminal.waitForRender();
+
+			const writes = terminal.getWrites();
+			assert.ok(writes.includes(imageSequence), "image placement should be drawn");
+			assert.ok(
+				!writes.includes(`\x1b[${imageLines.length - 1}A${imageSequence}`),
+				"taller-than-viewport images must keep the #4461 first-row placement path",
+			);
+
+			tui.stop();
+		} finally {
+			resetCapabilitiesCache();
+			setCellDimensions({ widthPx: 9, heightPx: 18 });
+		}
+	});
+
 	it("deletes changed image ids before drawing moved placements", async () => {
 		const terminal = new LoggingVirtualTerminal(40, 10);
 		const tui = new TUI(terminal);