Function injectionMsg

apps/vis/server/test/lib/context-projector.test.ts:542–545

(text: string)

      origin: { kind: 'user' as const },
    });
    const injectionMsg = (text: string) => ({
      role: 'user' as const, content: [{ type: 'text' as const, text }], toolCalls: [],
      origin: { kind: 'injection' as const },
    });
    // Layout: [u1, a1, u2, INJECTION, a2]. undo(1) walks from the end:
    //   a2  → removed (non-injection)
    //   INJECTION → skipped (kept), NOT counted