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.

6 files changed, 238 insertions, 232 deletions

diff --git a/src/tests/test_spectool.cc b/src/tests/test_spectool.cc
new file mode 100644
index 0000000..7581f0d
--- /dev/null
+++ b/src/tests/test_spectool.cc
@@ -0,0 +1,95 @@
+#include "audio/dct.h" // For DCT_SIZE
+#include "miniaudio.h"
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h> // For system()
+#include <vector>
+
+// Re-defining the header here to avoid dependency on the tool's source
+struct SpecHeader {
+  char magic[4];
+  int32_t version;
+  int32_t dct_size;
+  int32_t num_frames;
+};
+
+#define TEST_SAMPLE_RATE 32000
+#define TEST_DURATION_SECONDS 1
+#define TEST_FREQ 440.0f
+#define PI 3.14159265f
+
+int main() {
+  printf("Running spectool end-to-end test...\n");
+
+  const char *wav_path = "test_signal.wav";
+  const char *spec_path = "test_signal.spec";
+  const char *spectool_path =
+      "./spectool"; // Assumes ctest is run from `build` dir
+
+  // 1. Generate and save a WAV file
+  ma_encoder_config enc_config = ma_encoder_config_init(
+      ma_encoding_format_wav, ma_format_f32, 1, TEST_SAMPLE_RATE);
+  ma_encoder encoder;
+  if (ma_encoder_init_file(wav_path, &enc_config, &encoder) != MA_SUCCESS) {
+    printf("TEST FAILED: Could not initialize WAV encoder.\n");
+    return 1;
+  }
+
+  std::vector<float> pcm_data(TEST_SAMPLE_RATE * TEST_DURATION_SECONDS);
+  for (size_t i = 0; i < pcm_data.size(); ++i) {
+    pcm_data[i] = 0.5f * sinf(2.0f * PI * TEST_FREQ * i / TEST_SAMPLE_RATE);
+  }
+  ma_uint64 frames_written;
+  ma_encoder_write_pcm_frames(&encoder, pcm_data.data(), pcm_data.size(),
+                              &frames_written);
+  ma_encoder_uninit(&encoder);
+  printf("  Generated %s\n", wav_path);
+
+  // 2. Run spectool analyze
+  char command[512];
+  snprintf(command, sizeof(command), "%s analyze %s %s", spectool_path,
+           wav_path, spec_path);
+  printf("  Executing: %s\n", command);
+  int return_code = system(command);
+  assert(return_code == 0);
+  printf("  spectool executed successfully.\n");
+
+  // 3. Verify the output .spec file
+  FILE *f_spec = fopen(spec_path, "rb");
+  assert(f_spec != NULL);
+
+  SpecHeader header;
+  fread(&header, sizeof(SpecHeader), 1, f_spec);
+  assert(strncmp(header.magic, "SPEC", 4) == 0);
+  assert(header.version == 1);
+  assert(header.dct_size == DCT_SIZE);
+
+  int expected_frames = (TEST_SAMPLE_RATE * TEST_DURATION_SECONDS) / DCT_SIZE;
+  if ((TEST_SAMPLE_RATE * TEST_DURATION_SECONDS) % DCT_SIZE != 0) {
+    expected_frames++;
+  }
+  assert(header.num_frames == expected_frames);
+
+  printf("  .spec header verified.\n");
+
+  // Just check that we have some non-zero data
+  std::vector<float> spec_data(header.num_frames * header.dct_size);
+  fread(spec_data.data(), sizeof(float), spec_data.size(), f_spec);
+  fclose(f_spec);
+
+  double total_energy = 0.0;
+  for (float val : spec_data) {
+    total_energy += fabs(val);
+  }
+  assert(total_energy > 0.0);
+  printf("  .spec data seems valid.\n");
+
+  // 4. Cleanup
+  remove(wav_path);
+  remove(spec_path);
+  printf("  Cleaned up temporary files.\n");
+
+  printf("...spectool test PASSED!\n");
+  return 0;
+}
diff --git a/src/tests/test_spectool.cpp b/src/tests/test_spectool.cpp
deleted file mode 100644
index ae64cc3..0000000
--- a/src/tests/test_spectool.cpp
+++ /dev/null
@@ -1,91 +0,0 @@
-#include <stdio.h>
-#include <assert.h>
-#include <stdlib.h> // For system()
-#include <vector>
-#include <math.h>
-#include "miniaudio.h"
-#include "audio/dct.h" // For DCT_SIZE
-
-// Re-defining the header here to avoid dependency on the tool's source
-struct SpecHeader {
-    char magic[4];
-    int32_t version;
-    int32_t dct_size;
-    int32_t num_frames;
-};
-
-#define TEST_SAMPLE_RATE 32000
-#define TEST_DURATION_SECONDS 1
-#define TEST_FREQ 440.0f
-#define PI 3.14159265f
-
-int main() {
-    printf("Running spectool end-to-end test...\n");
-
-    const char* wav_path = "test_signal.wav";
-    const char* spec_path = "test_signal.spec";
-    const char* spectool_path = "./spectool"; // Assumes ctest is run from `build` dir
-
-    // 1. Generate and save a WAV file
-    ma_encoder_config enc_config = ma_encoder_config_init(ma_encoding_format_wav, ma_format_f32, 1, TEST_SAMPLE_RATE);
-    ma_encoder encoder;
-    if (ma_encoder_init_file(wav_path, &enc_config, &encoder) != MA_SUCCESS) {
-        printf("TEST FAILED: Could not initialize WAV encoder.\n");
-        return 1;
-    }
-
-    std::vector<float> pcm_data(TEST_SAMPLE_RATE * TEST_DURATION_SECONDS);
-    for (size_t i = 0; i < pcm_data.size(); ++i) {
-        pcm_data[i] = 0.5f * sinf(2.0f * PI * TEST_FREQ * i / TEST_SAMPLE_RATE);
-    }
-    ma_uint64 frames_written;
-    ma_encoder_write_pcm_frames(&encoder, pcm_data.data(), pcm_data.size(), &frames_written);
-    ma_encoder_uninit(&encoder);
-    printf("  Generated %s\n", wav_path);
-
-    // 2. Run spectool analyze
-    char command[512];
-    snprintf(command, sizeof(command), "%s analyze %s %s", spectool_path, wav_path, spec_path);
-    printf("  Executing: %s\n", command);
-    int return_code = system(command);
-    assert(return_code == 0);
-    printf("  spectool executed successfully.\n");
-
-    // 3. Verify the output .spec file
-    FILE* f_spec = fopen(spec_path, "rb");
-    assert(f_spec != NULL);
-    
-    SpecHeader header;
-    fread(&header, sizeof(SpecHeader), 1, f_spec);
-    assert(strncmp(header.magic, "SPEC", 4) == 0);
-    assert(header.version == 1);
-    assert(header.dct_size == DCT_SIZE);
-    
-    int expected_frames = (TEST_SAMPLE_RATE * TEST_DURATION_SECONDS) / DCT_SIZE;
-    if ((TEST_SAMPLE_RATE * TEST_DURATION_SECONDS) % DCT_SIZE != 0) {
-        expected_frames++;
-    }
-    assert(header.num_frames == expected_frames);
-
-    printf("  .spec header verified.\n");
-    
-    // Just check that we have some non-zero data
-    std::vector<float> spec_data(header.num_frames * header.dct_size);
-    fread(spec_data.data(), sizeof(float), spec_data.size(), f_spec);
-    fclose(f_spec);
-
-    double total_energy = 0.0;
-    for(float val : spec_data) {
-        total_energy += fabs(val);
-    }
-    assert(total_energy > 0.0);
-    printf("  .spec data seems valid.\n");
-
-    // 4. Cleanup
-    remove(wav_path);
-    remove(spec_path);
-    printf("  Cleaned up temporary files.\n");
-
-    printf("...spectool test PASSED!\n");
-    return 0;
-}
diff --git a/src/tests/test_synth.cc b/src/tests/test_synth.cc
new file mode 100644
index 0000000..3492057
--- /dev/null
+++ b/src/tests/test_synth.cc
@@ -0,0 +1,107 @@
+#include "audio/synth.h"
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+// A simple floating point comparison with a tolerance
+bool is_close(float a, float b, float epsilon = 1e-6f) {
+  return fabsf(a - b) < epsilon;
+}
+
+void test_registration() {
+  synth_init();
+  printf("Running test: Registration...\n");
+
+  float spec_buf_a[DCT_SIZE], spec_buf_b[DCT_SIZE];
+  Spectrogram spec = {spec_buf_a, spec_buf_b, 1};
+
+  // Fill up all slots
+  for (int i = 0; i < MAX_SPECTROGRAMS; ++i) {
+    int id = synth_register_spectrogram(&spec);
+    assert(id == i);
+  }
+
+  // Next one should fail
+  int fail_id = synth_register_spectrogram(&spec);
+  assert(fail_id == -1);
+
+  // Unregister one
+  synth_unregister_spectrogram(5);
+
+  // Now we should be able to register again in the freed slot
+  int new_id = synth_register_spectrogram(&spec);
+  assert(new_id == 5);
+
+  printf("...Registration test PASSED.\n");
+}
+
+void test_render() {
+  synth_init();
+  printf("Running test: Render...\n");
+
+  float spec_buf_a[DCT_SIZE] = {0};
+  Spectrogram spec = {spec_buf_a, nullptr, 1};
+
+  // Create a simple spectrum with one active bin
+  spec_buf_a[10] = 1.0f;
+
+  int id = synth_register_spectrogram(&spec);
+  assert(id != -1);
+
+  synth_trigger_voice(id, 1.0f, 0.0f);
+
+  float output_buffer[DCT_SIZE * 2] = {0}; // Stereo
+  synth_render(output_buffer, DCT_SIZE);
+
+  float total_energy = 0.0f;
+  for (int i = 0; i < DCT_SIZE * 2; ++i) {
+    total_energy += fabsf(output_buffer[i]);
+  }
+
+  // If we rendered a sound, the buffer should not be silent
+  assert(total_energy > 0.01f);
+
+  printf("...Render test PASSED.\n");
+}
+
+void test_update() {
+  synth_init();
+  printf("Running test: Update...\n");
+  float spec_buf_a[DCT_SIZE] = {0};
+  float spec_buf_b[DCT_SIZE] = {0};
+  Spectrogram spec = {spec_buf_a, spec_buf_b, 1};
+
+  spec_buf_a[10] = 1.0f; // Original sound
+  spec_buf_b[20] = 1.0f; // Updated sound
+
+  int id = synth_register_spectrogram(&spec);
+
+  // Begin update - should get back buffer B
+  float *back_buffer = synth_begin_update(id);
+  assert(back_buffer == spec_buf_b);
+
+  // We could modify it here, but it's already different.
+  // Let's just commit.
+  synth_commit_update(id);
+
+  // Now if we trigger a voice, it should play from buffer B.
+  // To test this, we'd need to analyze the output, which is complex.
+  // For this test, we'll just ensure the mechanism runs and we can
+  // begin an update on the *new* back buffer (A).
+  back_buffer = synth_begin_update(id);
+  assert(back_buffer == spec_buf_a);
+
+  printf("...Update test PASSED.\n");
+}
+
+int main() {
+  test_registration();
+  test_render();
+  test_update();
+
+  synth_shutdown();
+
+  printf("\nAll synth tests passed!\n");
+  return 0;
+}
diff --git a/src/tests/test_synth.cpp b/src/tests/test_synth.cpp
deleted file mode 100644
index 04b0373..0000000
--- a/src/tests/test_synth.cpp
+++ /dev/null
@@ -1,107 +0,0 @@
-#include "audio/synth.h"
-#include <stdio.h>
-#include <assert.h>
-#include <string.h>
-#include <math.h>
-
-// A simple floating point comparison with a tolerance
-bool is_close(float a, float b, float epsilon = 1e-6f) {
-    return fabsf(a - b) < epsilon;
-}
-
-void test_registration() {
-    synth_init();
-    printf("Running test: Registration...\n");
-    
-    float spec_buf_a[DCT_SIZE], spec_buf_b[DCT_SIZE];
-    Spectrogram spec = { spec_buf_a, spec_buf_b, 1 };
-
-    // Fill up all slots
-    for (int i = 0; i < MAX_SPECTROGRAMS; ++i) {
-        int id = synth_register_spectrogram(&spec);
-        assert(id == i);
-    }
-
-    // Next one should fail
-    int fail_id = synth_register_spectrogram(&spec);
-    assert(fail_id == -1);
-
-    // Unregister one
-    synth_unregister_spectrogram(5);
-
-    // Now we should be able to register again in the freed slot
-    int new_id = synth_register_spectrogram(&spec);
-    assert(new_id == 5);
-
-    printf("...Registration test PASSED.\n");
-}
-
-void test_render() {
-    synth_init();
-    printf("Running test: Render...\n");
-
-    float spec_buf_a[DCT_SIZE] = {0};
-    Spectrogram spec = { spec_buf_a, nullptr, 1 };
-    
-    // Create a simple spectrum with one active bin
-    spec_buf_a[10] = 1.0f; 
-
-    int id = synth_register_spectrogram(&spec);
-    assert(id != -1);
-
-    synth_trigger_voice(id, 1.0f, 0.0f);
-
-    float output_buffer[DCT_SIZE * 2] = {0}; // Stereo
-    synth_render(output_buffer, DCT_SIZE);
-
-    float total_energy = 0.0f;
-    for(int i = 0; i < DCT_SIZE * 2; ++i) {
-        total_energy += fabsf(output_buffer[i]);
-    }
-
-    // If we rendered a sound, the buffer should not be silent
-    assert(total_energy > 0.01f);
-
-    printf("...Render test PASSED.\n");
-}
-
-void test_update() {
-    synth_init();
-    printf("Running test: Update...\n");
-    float spec_buf_a[DCT_SIZE] = {0};
-    float spec_buf_b[DCT_SIZE] = {0};
-    Spectrogram spec = { spec_buf_a, spec_buf_b, 1 };
-    
-    spec_buf_a[10] = 1.0f; // Original sound
-    spec_buf_b[20] = 1.0f; // Updated sound
-
-    int id = synth_register_spectrogram(&spec);
-
-    // Begin update - should get back buffer B
-    float* back_buffer = synth_begin_update(id);
-    assert(back_buffer == spec_buf_b);
-
-    // We could modify it here, but it's already different.
-    // Let's just commit.
-    synth_commit_update(id);
-
-    // Now if we trigger a voice, it should play from buffer B.
-    // To test this, we'd need to analyze the output, which is complex.
-    // For this test, we'll just ensure the mechanism runs and we can
-    // begin an update on the *new* back buffer (A).
-    back_buffer = synth_begin_update(id);
-    assert(back_buffer == spec_buf_a);
-
-    printf("...Update test PASSED.\n");
-}
-
-int main() {
-    test_registration();
-    test_render();
-    test_update();
-
-    synth_shutdown();
-
-    printf("\nAll synth tests passed!\n");
-    return 0;
-}
diff --git a/src/tests/test_window.cc b/src/tests/test_window.cc
new file mode 100644
index 0000000..e23d97c
--- /dev/null
+++ b/src/tests/test_window.cc
@@ -0,0 +1,36 @@
+#include "audio/window.h"
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+
+// A simple floating point comparison with a tolerance
+bool is_close(float a, float b, float epsilon = 1e-6f) {
+  return fabsf(a - b) < epsilon;
+}
+
+int main() {
+  float window[WINDOW_SIZE];
+  hamming_window_512(window);
+
+  // Test 1: Window should start and end at the same small value
+  assert(is_close(window[0], 0.08f));
+  assert(is_close(window[WINDOW_SIZE - 1], 0.08f));
+  printf("Test 1 passed: Window start and end values are correct.\n");
+
+  // Test 2: Window should be symmetric
+  for (int i = 0; i < WINDOW_SIZE / 2; ++i) {
+    assert(is_close(window[i], window[WINDOW_SIZE - 1 - i]));
+  }
+  printf("Test 2 passed: Window is symmetric.\n");
+
+  // Test 3: The two middle points of the even-sized window should be equal and
+  // the peak.
+  assert(is_close(window[WINDOW_SIZE / 2 - 1], window[WINDOW_SIZE / 2]));
+  assert(window[WINDOW_SIZE / 2] >
+         window[WINDOW_SIZE / 2 - 2]); // Should be greater than neighbors
+  printf("Test 3 passed: Window peak is correct for even size.\n");
+
+  printf("All tests passed for Hamming window!\n");
+
+  return 0;
+}
diff --git a/src/tests/test_window.cpp b/src/tests/test_window.cpp
deleted file mode 100644
index 1667dab..0000000
--- a/src/tests/test_window.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-#include "audio/window.h"
-#include <stdio.h>
-#include <math.h>
-#include <assert.h>
-
-// A simple floating point comparison with a tolerance
-bool is_close(float a, float b, float epsilon = 1e-6f) {
-    return fabsf(a - b) < epsilon;
-}
-
-int main() {
-    float window[WINDOW_SIZE];
-    hamming_window_512(window);
-
-    // Test 1: Window should start and end at the same small value
-    assert(is_close(window[0], 0.08f));
-    assert(is_close(window[WINDOW_SIZE - 1], 0.08f));
-    printf("Test 1 passed: Window start and end values are correct.\n");
-
-    // Test 2: Window should be symmetric
-    for (int i = 0; i < WINDOW_SIZE / 2; ++i) {
-        assert(is_close(window[i], window[WINDOW_SIZE - 1 - i]));
-    }
-    printf("Test 2 passed: Window is symmetric.\n");
-
-    // Test 3: The two middle points of the even-sized window should be equal and the peak.
-    assert(is_close(window[WINDOW_SIZE / 2 - 1], window[WINDOW_SIZE / 2]));
-    assert(window[WINDOW_SIZE / 2] > window[WINDOW_SIZE / 2 - 2]); // Should be greater than neighbors
-    printf("Test 3 passed: Window peak is correct for even size.\n");
-    
-    printf("All tests passed for Hamming window!\n");
-
-    return 0;
-}