PHLEGM v6 Display FPS Overlay - 2026-10-02

Every active emulated display now superimposes measured host presentation FPS in the lower-left of the emulated picture. The overlay counts only newly presented emulated frame numbers, so duplicate WM_PAINT traffic does not inflate the reading. It uses host wall-clock time, updates on a rolling half-second window, and is drawn after the final presentation blit with transparent white text plus a one-pixel black shadow. The counter is host-only: it is not written into emulated framebuffer data, screenshots, sessions, states, or machine timing.
