feat: Implement spectool & specview; refactor coding style; update docs

This commit introduces new tools for spectrogram manipulation and visualization, establishes a consistent coding style, and updates project documentation.

Key changes include:

- **Spectrogram Tools:

  - : A command-line utility for analyzing WAV/MP3 files into custom  spectrogram format and playing back these spectrograms via the synth engine.

  - : A command-line tool for visualizing  spectrogram files as ASCII art in the console.

- **Coding Style Enforcement:

  - Added a  configuration file enforcing LLVM-based style with 2-space indentation, no tabs, and an 80-column line limit.

  - Renamed all C++ source files from  to  for project consistency.

  - Applied automatic formatting using
exit across the entire codebase.

- **Documentation & Workflow:

  - Created  to define a commit policy requiring tests to pass before committing.

  - Updated  with instructions for building and using  and , and referenced .

  - Updated  and  to reflect the new tools, audio architecture decisions (real-time additive synthesis, double-buffering for dynamic updates, WAV/MP3 support), coding style, and development workflow.

- **Build System:

  - Modified  to:

    - Include new targets for  and  under the  option.

    - Update source file extensions to .

    - Add a new end-to-end test for  to the  suite.

1 files changed, 70 insertions, 0 deletions

diff --git a/src/main.cc b/src/main.cc
new file mode 100644
index 0000000..56d755c
--- /dev/null
+++ b/src/main.cc
@@ -0,0 +1,70 @@
+#include "audio/audio.h"
+#include "audio/synth.h"
+#include "gpu/gpu.h"
+#include "platform.h"
+#include "util/math.h"
+#include <math.h>
+#include <string.h>
+
+#define DEMO_BPM 120.0f
+#define SECONDS_PER_BEAT (60.0f / DEMO_BPM)
+#define SPEC_FRAMES 16
+
+static float g_spec_buffer_a[SPEC_FRAMES * DCT_SIZE];
+static float g_spec_buffer_b[SPEC_FRAMES * DCT_SIZE];
+
+void generate_tone(float *buffer, float freq) {
+  memset(buffer, 0, SPEC_FRAMES * DCT_SIZE * sizeof(float));
+  for (int frame = 0; frame < SPEC_FRAMES; ++frame) {
+    float *spec_frame = buffer + frame * DCT_SIZE;
+    float amplitude = powf(1.0f - (float)frame / SPEC_FRAMES, 2.0f);
+
+    int bin = (int)(freq / (32000.0f / 2.0f) * DCT_SIZE);
+    if (bin > 0 && bin < DCT_SIZE) {
+      spec_frame[bin] = amplitude;
+    }
+  }
+}
+
+int main() {
+  platform_init();
+  gpu_init(platform_get_window());
+  audio_init();
+
+  generate_tone(g_spec_buffer_a, 440.0f); // A4
+  generate_tone(g_spec_buffer_b, 880.0f); // A5
+
+  Spectrogram spec = {g_spec_buffer_a, g_spec_buffer_b, SPEC_FRAMES};
+  int tone_id = synth_register_spectrogram(&spec);
+
+  double last_beat_time = 0.0;
+  int beat_count = 0;
+
+  while (!platform_should_close()) {
+    platform_poll();
+
+    double current_time = platform_get_time();
+    if (current_time - last_beat_time > SECONDS_PER_BEAT) {
+      synth_trigger_voice(tone_id, 0.5f, 0.0f);
+      last_beat_time = current_time;
+      beat_count++;
+
+      if (beat_count == 8) {
+        // Time to update the sound!
+        float *back_buffer = synth_begin_update(tone_id);
+        if (back_buffer) {
+          generate_tone(back_buffer, 220.0f); // A3
+          synth_commit_update(tone_id);
+        }
+      }
+    }
+
+    gpu_draw();
+    audio_update();
+  }
+
+  audio_shutdown();
+  gpu_shutdown();
+  platform_shutdown();
+  return 0;
+}