Clear stale float offsets when the overlay host returns to flow

The overlay host floats absolutely over the landing screen, and the
un-float path only flipped position back to relative. Yoga treats the
leftover top inset as a relative offset, so after any overlay had
opened on the landing, every later in-session overlay — the slash
popup, the model picker — rendered that many rows below its flow
slot, ending up under the prompt and clipped off the screen.

Author: TheGreatAxios

src/tui/overlay-float-reset.test.ts

@@ -0,0 +1,56 @@
+import { expect, test } from "bun:test"
+
+import { withTestRenderer } from "./harness"
+import { appendStreamRow, closeInsetOverlay, createAppShell } from "./shell"
+import { openModelPickerOverlay } from "./overlays"
+import type { PaletteCommand } from "./command-catalog"
+
+const CATALOG: readonly PaletteCommand[] = [
+  { id: "model", label: "/model" },
+  { id: "mcp", label: "/mcp" },
+]
+
+// Regression: the overlay host floats absolutely over the landing (top set to
+// a large row offset) but is an in-flow band once a transcript exists.
+// Un-floating used to leave the absolute insets behind, and under relative
+// positioning a stale top offsets the band downward — the slash popup rendered
+// below the prompt, clipped off the bottom of the screen.
+test("slash popup stays above the prompt after a landing-floated overlay", async () => {
+  await withTestRenderer(
+    async (h) => {
+      const shell = createAppShell(h.renderer, {
+        terminal: { columns: 120, rows: 50 },
+        wireKeys: true,
+        run: "idle",
+        paletteCatalog: CATALOG,
+      })
+      try {
+        // Landing: overlay floats absolutely with a large top offset.
+        openModelPickerOverlay(shell, { items: ["codex/def / gpt-5.6-sol"] })
+        await h.renderOnce()
+        closeInsetOverlay(shell)
+        await h.renderOnce()
+
+        // Transcript starts; overlays are in-flow bands from here on.
+        appendStreamRow(shell, { role: "user", text: "hi" })
+        appendStreamRow(shell, { role: "assistant", text: "Hi! What can I help you with?" })
+        await h.renderOnce()
+
+        h.pressKey("/")
+        h.pressKey("m")
+        h.pressKey("o")
+        await h.renderOnce()
+        const frame = h.captureCharFrame()
+        const lines = frame.split("\n")
+        const popupRow = lines.findIndex((l) => l.includes("/model"))
+        const promptRow = lines.findIndex((l) => l.includes("/mo") && !l.includes("/model"))
+        expect(popupRow).toBeGreaterThanOrEqual(0)
+        expect(promptRow).toBeGreaterThanOrEqual(0)
+        expect(popupRow).toBeLessThan(promptRow)
+      } finally {
+        shell.dispose()
+      }
+    },
+    { width: 120, height: 50 },
+  )
+})

src/tui/shell.ts

@@ -1193,6 +1193,13 @@ function floatOverlayHost(
   if (!floating) {
     host.position = "relative"
     host.zIndex = 0
+    // A previous landing float left absolute insets behind. Under relative
+    // positioning those same values act as offsets from the in-flow slot, so
+    // a stale top pushes the band that many rows below the prompt — clear
+    // them so the band sits where the flow put it.
+    host.top = 0
+    host.left = 0
+    host.width = "100%"
     return
   }
   host.position = "absolute"