fix(onboarding): calibration Tuner step no longer exposes the input-select overlay (#577)

Tester: "at the tune step, pressing the Tuner button starts a second wizard at
the input-select step."

Root cause is stacked full-screen overlays. During onboarding the input-setup
flow runs as #input-setup-overlay (z-210) on top of the onboarding modal
#v3-onboarding (z-200), and note_detect's Calibration Wizard (z-300) launches on
top of that. When the player opens the Tuner, that wizard minimizes itself to
transparent + pointer-events:none so the Tuner (z-1000) is usable — but the
input-setup overlay underneath, still showing its "select your input" card, then
shows through behind the floating tuner and reads as a second wizard.

Two targeted hides so only the active surface is visible:
- input_setup: hide #input-setup-overlay while launchCalibration runs; restore on
  its onDone/onCancel (one always fires on close), so the calibration wizard /
  tuner own the screen.
- onboarding runInputSetup: hide #v3-onboarding for the whole input-setup phase
  (its own overlay replaces it visually); restore in finally before advancing to
  the calibration-challenge step.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/input_setup/screen.js

@@ -163,10 +163,25 @@
 
                 host.querySelector('[data-is-cal]').addEventListener('click', () => {
                     if (hasDetector) {
+                        // Hide our own full-screen overlay while note_detect's
+                        // Calibration Wizard runs on top. That wizard goes
+                        // transparent (pointer-events:none) when it minimizes to
+                        // expose the Tuner; if our overlay stayed up it would show
+                        // through — covering the tuner with the still-mounted
+                        // "select your input" card and looking like a second
+                        // wizard at the input step. Restore it on done/cancel
+                        // (one of which always fires when that wizard closes).
+                        const ov = document.getElementById('input-setup-overlay');
+                        const prevDisplay = ov ? ov.style.display : '';
+                        if (ov) ov.style.display = 'none';
+                        const restore = () => {
+                            const o = document.getElementById('input-setup-overlay');
+                            if (o) o.style.display = prevDisplay;
+                        };
                         window.noteDetect.launchCalibration({
                             instrument: inst,
-                            onDone: () => advance(inst, true),
-                            onCancel: () => { /* stay on this panel; user can skip or retry */ },
+                            onDone: () => { restore(); advance(inst, true); },
+                            onCancel: () => { restore(); /* stay on this panel; user can skip or retry */ },
                         });
                     } else {
                         advance(inst, true);