Assert transcript rows by content, not frame-wide substring absence

Checking a rendered frame for the absence of "agent" anywhere breaks
in any checkout whose directory name contains that substring (the
footer prints the workspace path), including any path containing
"subagent". Scope the assertion to the rows that actually carry a
voice label instead.

Author: TheGreatAxios

src/tui-opentui/shell.test.ts

@@ -355,8 +355,9 @@ describe("product skin: stream + queue + overlay", () => {
           expect(frame).toContain("hi there")
           expect(frame).toContain("bash")
           // One agent is answering, so no row spends columns naming it.
-          expect(frame).not.toContain("agent")
-          expect(frame).not.toContain(" tool ")
+          const inkRows = frame.split("\n").filter((row) => row.trim().length > 0)
+          expect(inkRows.filter((row) => row.includes("● agent"))).toHaveLength(0)
+          expect(inkRows.filter((row) => row.includes(" tool "))).toHaveLength(0)
           // User row content is in the scroll buffer (pure paint covered in stream.test).
           expect(
             paintStreamRow(

src/tui-opentui/transcript-layout.test.ts

@@ -73,8 +73,8 @@ describe("transcript turn layout", () => {
         expect(row).toBeDefined()
         const painted = row as string
         expect(painted.indexOf("listing")).toBe(resolveSideMargin(80))
-        expect(frame).not.toContain("agent")
-        expect(frame).not.toContain("you")
+        expect(rowsContaining(frame, "● agent")).toHaveLength(0)
+        expect(rowsContaining(frame, "● you")).toHaveLength(0)
       },
     )
   })