feat: add client tests, status FIFO, and evaluation docs

client/src/tui.c

@@ -11,8 +11,10 @@
 #include <math.h>
 
 /* ---------- FIFO command helper ---------- */
-static int send_command(const char *cmd) {
-    int fd = open("/tmp/looper_cmd", O_WRONLY);
+int send_command(const char *cmd) {
+    const char *fifo_path = getenv("LOOPER_CMD_FIFO");
+    if (!fifo_path) fifo_path = "/tmp/looper_cmd";
+    int fd = open(fifo_path, O_WRONLY | O_NONBLOCK);
     if (fd < 0) return -1;
     size_t len = strlen(cmd);
     int n = write(fd, cmd, len);

client/src/tui.h

@@ -4,5 +4,6 @@
 void tui_init(void);
 void tui_run(void);
 void tui_cleanup(void);
+int send_command(const char *cmd);
 
 #endif