refactor(audio): extract AutoEQ proxy commands into own module

Pull autoeq_entries + autoeq_fetch_profile out of audio/commands.rs
into audio/autoeq_commands.rs (~52 LOC). They proxy autoeq.app +
GitHub raw content via Rust to bypass WebView CORS — pure HTTP-fetch
flow with no playback state coupling, so they don't need to live next
to the playback orchestrator.

lib.rs invoke_handler updated to register them under
`audio::autoeq_commands::*`. audio/commands.rs: 1830 → 1784 LOC.

src-tauri/src/audio/autoeq_commands.rs

@@ -0,0 +1,52 @@
+//! AutoEQ proxy commands: fetch entry list and FixedBandEQ profiles from
+//! GitHub via Rust to bypass WebView CORS.
+
+use tauri::State;
+
+use super::engine::{audio_http_client, AudioEngine};
+
+/// Proxy: fetches https://autoeq.app/entries via Rust to bypass WebView CORS restrictions.
+#[tauri::command]
+pub async fn autoeq_entries(state: State<'_, AudioEngine>) -> Result<String, String> {
+    audio_http_client(&state)
+        .get("https://autoeq.app/entries")
+        .send().await.map_err(|e| e.to_string())?
+        .text().await.map_err(|e| e.to_string())
+}
+
+/// Fetches the AutoEQ FixedBandEQ profile for a specific headphone from GitHub raw content.
+///
+/// Directory layout in the AutoEQ repo:
+///   results/{source}/{form}/{name}/{name} FixedBandEQ.txt           (most sources)
+///   results/{source}/{rig} {form}/{name}/{name} FixedBandEQ.txt     (crinacle — rig-prefixed dir)
+///
+/// We try the rig-prefixed path first (when rig is present), then fall back to form-only.
+#[tauri::command]
+pub async fn autoeq_fetch_profile(
+    name: String,
+    source: String,
+    rig: Option<String>,
+    form: String,
+    state: State<'_, AudioEngine>,
+) -> Result<String, String> {
+    let base = "https://raw.githubusercontent.com/jaakkopasanen/AutoEq/master/results";
+    let filename = format!("{} FixedBandEQ.txt", name);
+
+    let candidates: Vec<String> = if let Some(ref r) = rig {
+        vec![
+            format!("{}/{}/{} {}/{}/{}", base, source, r, form, name, filename),
+            format!("{}/{}/{}/{}/{}", base, source, form, name, filename),
+        ]
+    } else {
+        vec![format!("{}/{}/{}/{}/{}", base, source, form, name, filename)]
+    };
+
+    for url in &candidates {
+        let resp = audio_http_client(&state).get(url).send().await.map_err(|e| e.to_string())?;
+        if resp.status().is_success() {
+            return resp.text().await.map_err(|e| e.to_string());
+        }
+    }
+
+    Err(format!("FixedBandEQ profile not found for '{}'", name))
+}

src-tauri/src/audio/commands.rs

@@ -1498,51 +1498,6 @@ pub fn audio_update_replay_gain(
     );
 }
 
-/// Proxy: fetches https://autoeq.app/entries via Rust to bypass WebView CORS restrictions.
-#[tauri::command]
-pub async fn autoeq_entries(state: State<'_, AudioEngine>) -> Result<String, String> {
-    audio_http_client(&state)
-        .get("https://autoeq.app/entries")
-        .send().await.map_err(|e| e.to_string())?
-        .text().await.map_err(|e| e.to_string())
-}
-
-/// Fetches the AutoEQ FixedBandEQ profile for a specific headphone from GitHub raw content.
-///
-/// Directory layout in the AutoEQ repo:
-///   results/{source}/{form}/{name}/{name} FixedBandEQ.txt           (most sources)
-///   results/{source}/{rig} {form}/{name}/{name} FixedBandEQ.txt     (crinacle — rig-prefixed dir)
-///
-/// We try the rig-prefixed path first (when rig is present), then fall back to form-only.
-#[tauri::command]
-pub async fn autoeq_fetch_profile(
-    name: String,
-    source: String,
-    rig: Option<String>,
-    form: String,
-    state: State<'_, AudioEngine>,
-) -> Result<String, String> {
-    let base = "https://raw.githubusercontent.com/jaakkopasanen/AutoEq/master/results";
-    let filename = format!("{} FixedBandEQ.txt", name);
-
-    let candidates: Vec<String> = if let Some(ref r) = rig {
-        vec![
-            format!("{}/{}/{} {}/{}/{}", base, source, r, form, name, filename),
-            format!("{}/{}/{}/{}/{}", base, source, form, name, filename),
-        ]
-    } else {
-        vec![format!("{}/{}/{}/{}/{}", base, source, form, name, filename)]
-    };
-
-    for url in &candidates {
-        let resp = audio_http_client(&state).get(url).send().await.map_err(|e| e.to_string())?;
-        if resp.status().is_success() {
-            return resp.text().await.map_err(|e| e.to_string());
-        }
-    }
-
-    Err(format!("FixedBandEQ profile not found for '{}'", name))
-}
 
 #[tauri::command]
 pub fn audio_set_eq(gains: [f32; 10], enabled: bool, pre_gain: f32, state: State<'_, AudioEngine>) {

src-tauri/src/audio/mod.rs

@@ -3,6 +3,7 @@
 //! Implementation is split into submodules (`sources`, `decode`, `stream`, `commands`, …)
 //! for navigation; behavior matches the historical single `audio.rs` file.
 
+pub mod autoeq_commands;
 mod codec;
 pub mod commands;
 mod decode;

src-tauri/src/lib.rs

@@ -395,8 +395,8 @@ pub fn run() {
             audio::commands::audio_set_volume,
             audio::commands::audio_update_replay_gain,
             audio::commands::audio_set_eq,
-            audio::commands::autoeq_entries,
-            audio::commands::autoeq_fetch_profile,
+            audio::autoeq_commands::autoeq_entries,
+            audio::autoeq_commands::autoeq_fetch_profile,
             audio::commands::audio_preload,
             audio::commands::audio_play_radio,
             audio::preview::audio_preview_play,