fix(windows): unify config/data dir and add service log file

config_dir() on Windows now returns data_dir() (ProgramData) so config,
services.json, and log file are in the same place for both interactive
and service contexts. Service mode writes logs to numa.log via
env_logger pipe. Dashboard shows correct log path per OS.

src/lib.rs

@@ -101,14 +101,11 @@ where
 /// Linux root daemon: /var/lib/numa (FHS) — falls back to /usr/local/var/numa
 ///                    if a pre-v0.10.1 install already lives there.
 /// macOS root daemon: /usr/local/var/numa (Homebrew prefix)
-/// Windows: %APPDATA%\numa
+/// Windows: %PROGRAMDATA%\numa (same as data_dir — no per-user config on Windows)
 pub fn config_dir() -> std::path::PathBuf {
     #[cfg(windows)]
     {
-        std::path::PathBuf::from(
-            std::env::var("APPDATA").unwrap_or_else(|_| "C:\\ProgramData".into()),
-        )
-        .join("numa")
+        data_dir()
     }
     #[cfg(not(windows))]
     {