Why: The ALLOWED_REPEAT_FREQ branch in handle_rx had `except e:` —
syntactically valid Python only if `e` happens to be bound to an
exception class, which it isn't. The first time the inner read loop
actually raised, the except clause itself would raise NameError
("name 'e' is not defined") and propagate out of the handler. The
proposal correctly notes this is unreachable in practice today
because `int.from_bytes(b"", ...)` returns 0 so the loop terminates
cleanly, but it is a latent footgun. Replace with the standard
`except Exception as e:` form and swap the `print(e)` for a proper
`logger.warning(...)` call to match the rest of the file (which uses
the module logger, not stdout).
Refs: Forensics report finding F11 (S3)
Why: The LOGIN_FAILED handler in handle_rx referenced an undefined
identifier `pbuf` instead of the local BytesIO `dbuf`. Firmware emits
PUSH_CODE_LOGIN_FAIL as a fixed 8-byte frame, which trivially
satisfies the `len(data) > 7` guard, so every remote auth failure
raised NameError. The sibling LOGIN_SUCCESS handler a few lines above
already uses `dbuf.read(6).hex()` correctly; this commit aligns the
LOGIN_FAILED branch with the same pattern.
Refs: Forensics report finding F10 (S1)
Why: handle_rx is invoked from a detached task in MessageReader, so any
exception escaping its ~850-line if/elif dispatch is silently swallowed
by asyncio as "Task exception was never retrieved." The only crash
guard previously was a single try/except IndexError around the first
byte read; everything past line 73 was unguarded. This commit adds an
umbrella try: ... except Exception as e: around the entire dispatch
body that logs the exception class, message, raw frame hex, and full
traceback via logger.error. The umbrella neutralizes the crash surface
of F10, F11, N07, N08, R01, NEW-B, and NEW-C, which the next commits
will then fix individually now that they are observable.
Refs: Forensics report finding F06 (umbrella crash protection)
