Terminal oscilloscope with CRT phosphor physics

- CRT boot/shutdown animations (ported from AetherTune)
- Y-T (time-domain) and X-Y (Lissajous) display modes
- Phosphor persistence with bloom and decay
- Half-block rendering for 2x vertical resolution
- Live audio capture via ffmpeg/PulseAudio monitor
- Gain and time/div controls, grid toggle, freeze

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

demo.tape

@@ -0,0 +1,16 @@
+Output demo.gif
+Output demo.png
+
+Set Shell "bash"
+Set FontSize 14
+Set Width 800
+Set Height 600
+Set Theme "Dracula"
+
+Type "./crt"
+Enter
+Sleep 4s
+Type "m"
+Sleep 2.5s
+Type "q"
+Sleep 2.5s