refactor: move log_line to openwa-core for shared logging

Move log_line() from openwa-wormkit to openwa_core::log so that core
types (e.g. DSSound::load_wav) can emit debug logging. openwa-wormkit
re-exports via pub use.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/openwa-core/src/lib.rs

@@ -11,6 +11,7 @@ pub mod input;
 pub mod render;
 
 pub mod fixed;
+pub mod log;
 pub mod task;
 pub mod address;
 pub mod rebase;

crates/openwa-core/src/log.rs

@@ -0,0 +1,12 @@
+//! Shared logging — writes to `OpenWA.log` in the working directory.
+
+/// Append a line to `OpenWA.log`.
+pub fn log_line(msg: &str) -> std::io::Result<()> {
+    use std::io::Write;
+    let mut f = std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open("OpenWA.log")?;
+    writeln!(f, "{msg}")?;
+    Ok(())
+}

crates/openwa-wormkit/src/lib.rs

@@ -38,15 +38,7 @@ unsafe extern "system" fn DllMain(
 // Logging
 // ---------------------------------------------------------------------------
 
-pub fn log_line(msg: &str) -> std::io::Result<()> {
-    use std::io::Write;
-    let mut f = std::fs::OpenOptions::new()
-        .create(true)
-        .append(true)
-        .open("OpenWA.log")?;
-    writeln!(f, "{msg}")?;
-    Ok(())
-}
+pub use openwa_core::log::log_line;
 
 fn clear_log() -> std::io::Result<()> {
     std::fs::write("OpenWA.log", "")?;