A key sent through the Debug Console could turn the screen "off" for a tick

The `key` command stamps the power timer from millis(); the power tick
then compared with its pass's older time, and the unsigned difference read
as 49 days without a key. The screen state went Off for one tick, and the
next key was swallowed as a wake-up: about one remote key in twenty-five.
Keys from the keyboard pass the loop's own time and were never affected.
The same shape as #46. PowerPolicy::update now treats a stamp from the
future as "just now", with a test.

rdbg.py: piped lines written while it was still connecting stayed in
Python's read buffer until the next line arrived (readline() behind
select()). It reads the descriptor directly now.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

scripts/rdbg.py

@@ -224,10 +224,15 @@ def interactive(sock):
             sys.stdout.write(data.decode(errors="replace"))
             sys.stdout.flush()
         if sys.stdin in ready:
-            line = sys.stdin.readline()
-            if not line:
+            # Straight from the descriptor: readline() takes every waiting line into Python's own
+            # buffer and hands over one, and select() then sees nothing more to read. Piped input
+            # written while we were still connecting got stuck until the next line came.
+            data = os.read(sys.stdin.fileno(), 4096)
+            if not data:
                 return
-            sock.sendall(line.encode())
+            sock.setblocking(True)
+            sock.sendall(data)
+            sock.setblocking(False)
 
 
 def main():