v0.4.5

Added

• Persistent file logging. All tracing output now goes to both
  stderr and a daily-rotating log file under the config directory
  (~/.config/clipboardwire/clipboardwire.log.YYYY-MM-DD on Linux).
  If the process disappears unexpectedly, the log file shows what
  happened last.
• Panic hook with crash file. Panics are caught by a custom hook
  that writes the panic message plus a full backtrace to
  ~/.config/clipboardwire/crash.log before aborting. This survives
  even if the tracing layer hasn't flushed yet.