connectContext() throws std::runtime_error when pa_context_connect() fails.
It was called directly from contextStateCb (the libpulse mainloop thread,
running pure-C callback frames) on the PA_CONTEXT_FAILED reconnect path, so on
a pipewire/pulse restart the exception unwound across the C callback boundary
and triggered std::terminate/SIGABRT.
Add reconnectContext() noexcept which wraps connectContext() and logs failures
instead of throwing, and use it from the callback. Guard against the
FAILED -> connect -> FAILED recursion/busy loop with a reentrancy flag. The
constructor-time connectContext() still throws as before.
Fixes#5141.