Rename crt → osc throughout

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

src/osc.nim

@@ -0,0 +1,86 @@
+## CRT Oscilloscope — terminal-based oscilloscope with phosphor physics.
+##
+## Features:
+##   - 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 2× vertical resolution
+##   - Live audio capture via ffmpeg/PulseAudio or demo signal
+
+import illwill, os
+import osc/[effects, phosphor, scope, audio]
+
+proc exitProc() {.noconv.} =
+  illwillDeinit()
+  showCursor()
+  quit(0)
+
+proc main() =
+  illwillInit(fullscreen = true)
+  setControlCHook(exitProc)
+  hideCursor()
+
+  let w = terminalWidth()
+  let h = terminalHeight()
+  var tb = newTerminalBuffer(w, h)
+
+  crtTurnOn(tb, w, h)
+
+  var scope = initScope(w, h)
+  var audio = startAudio()
+  var running = true
+
+  while running:
+    if not scope.frozen:
+      audio.readSamples(scope)
+
+    scope.phosphor.decay()
+
+    if not scope.frozen:
+      scope.renderTrace()
+
+    tb = newTerminalBuffer(w, h)
+    scope.phosphor.render(tb)
+    drawGraticule(tb, w, h, scope.grid)
+    drawHUD(tb, w, h, scope, audio.sourceLabel)
+    tb.display()
+
+    let key = getKey()
+    case key
+    of Key.Q, Key.Escape:
+      running = false
+    of Key.M:
+      scope.mode = if scope.mode == ModeYT: ModeXY else: ModeYT
+    of Key.Plus, Key.Equals:
+      scope.gain = min(scope.gain * 1.3, 20.0)
+    of Key.Minus:
+      scope.gain = max(scope.gain / 1.3, 0.5)
+    of Key.RightBracket:
+      scope.timeDiv = min(scope.timeDiv * 1.5, 16.0)
+    of Key.LeftBracket:
+      scope.timeDiv = max(scope.timeDiv / 1.5, 0.25)
+    of Key.Space:
+      scope.frozen = not scope.frozen
+    of Key.G:
+      scope.grid = case scope.grid
+        of gsGrid: gsCross
+        of gsCross: gsOff
+        of gsOff: gsGrid
+    of Key.D:
+      audio.cyclePreset()
+    else:
+      discard
+
+    sleep(16)
+
+  audio.stop()
+  crtTurnOff(tb, w, h)
+
+  tb = newTerminalBuffer(w, h)
+  tb.display()
+  sleep(100)
+  illwillDeinit()
+  showCursor()
+
+when isMainModule:
+  main()