fix: reopen FIFO on EOF to prevent blocking on subsequent writes

Co-authored-by: aider (deepseek/deepseek-reasoner) <aider@aider.chat>

src/pipe.c

@@ -7,6 +7,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ -19,12 +20,15 @@ extern spsc_queue_t cmd_queue_main_fifo;
 
 static void *pipe_thread_func(void *arg) {
   (void)arg;
+  char line[LINE_MAX];
+
+  while (1) {
     FILE *fifo = fopen(FIFO_PATH, "r");
     if (!fifo) {
       perror("fopen fifo");
       return NULL;
     }
-  char line[LINE_MAX];
+
     while (fgets(line, sizeof(line), fifo)) {
       /* strip newline */
       size_t len = strlen(line);
@@ -69,8 +73,14 @@ static void *pipe_thread_func(void *arg) {
       }
       /* ignore unknown lines */
     }
+    /* EOF – all writers closed, reopen for next connection */
     fclose(fifo);
-  return NULL;
+    {
+      struct timespec ts = {.tv_sec = 0, .tv_nsec = 50000000};
+      nanosleep(&ts, NULL);
+    } /* small pause before retrying */
+  }
+  return NULL; /* unreachable */
 }
 
 int pipe_start_reader(void) {