Handle terminal resize dynamically

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

src/osc.nim

@@ -19,8 +19,8 @@ proc main() =
   setControlCHook(exitProc)
   hideCursor()
 
-  let w = terminalWidth()
+  var w = terminalWidth()
-  let h = terminalHeight()
+  var h = terminalHeight()
   var tb = newTerminalBuffer(w, h)
 
   crtTurnOn(tb, w, h)
@@ -30,6 +30,13 @@ proc main() =
   var running = true
 
   while running:
+    let nw = terminalWidth()
+    let nh = terminalHeight()
+    if nw != w or nh != h:
+      w = nw
+      h = nh
+      scope.resize(w, h)
+
     if not scope.frozen:
       audio.readSamples(scope)
 

src/osc/scope.nim

@@ -39,6 +39,10 @@ proc initScope*(w, h: int): Scope =
 proc w*(s: Scope): int = s.phosphor.w
 proc h*(s: Scope): int = s.phosphor.h
 
+proc resize*(scope: var Scope, w, h: int) =
+  if w == scope.w and h == scope.h: return
+  scope.phosphor = initPhosphor(w, h)
+
 # ── Trace rendering ──────────────────────────────────────────────────
 
 proc renderTrace*(scope: var Scope) =