feat: add Tuner and Tuner Codex experiments

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: diwakergupta

README.md

@@ -12,6 +12,8 @@ This repository is a collection of vibe-coded experiments, tools, and demos by [
 - [ErgoCoach](./ergocoach)
 - [ErgoCoach - Kimi 2.5 version](./ergo-kimi/)
 - [Maze Runner](./mazerunner/)
+- [Tuner](./tuner/)
+- [Tuner Codex](./tuner-codex/)
 
 ## Structure
 

tuner-codex/README.md

@@ -0,0 +1,14 @@
+# Tuner Codex
+
+A fast, static, browser-based chromatic tuner built as a single `index.html` file. It uses the Web Audio API and an autocorrelation pitch detector to show:
+
+- detected note + octave
+- frequency in Hz
+- cents deviation
+- flat/perfect/sharp horizontal meter
+
+It includes intelligent smoothing, note stability lock, freeze-on-meter tap, mobile-friendly layout, settings (A4/theme/sound/show-frequency), and localStorage preferences.
+
+## Prompt
+
+Build a tuner app in the `tuner-codex` directory, based on this spec [tuner-spec.md](tuner-codex/tuner-spec.md)