v1.14.9

fix: self-heal now tears down the DVR session before reconnecting

v1.14.8's watchdog correctly detected the frozen cold-start pattern and
triggered recovery, but recreating the HLS.js instance against the same
manifest URL just reattached to the same stuck CC4C session server-side,
getting caught in the same buffer-hole/stall loop. Console diagnostics
showed clean playback only started after a real manual stop, which calls
stopLiveDvrSession() first. Self-heal now does the same before reconnecting,
with a short pause mirroring the natural gap a manual stop/reopen has.