Correct the media stage bound to connected - #704

Two corrections to the live view embedding guidance, plus a pass over the prose that changed.

The media reason row. It said the bound expires if ICE never reached checking. Since kernel-images#417 the client keeps the media bound armed through connected, so it expires only if ICE never arrives at connected or completed — completed is the other way a healthy connect can land when gathering is already done. An embedder branching on reason would otherwise expect media to fire earlier than it does. This row is the one #698 carried, which this PR supersedes.

The example watchdog. It remounted 15s after mount. The client's connect bounds run in sequence — transport, then signaling, then media — and sum to 28s, so an embedder following the snippet tore the frame down before the client could report which stage stalled. That is the media stage, which is the one most likely to have stalled, so the guidance was suppressing the diagnosis it was written to enable. The example now uses 35s, and the prose says why the timer needs room above the budget: it also covers loading the frame, including waking a browser that has gone to sleep.

The note claiming KERNEL_CONNECTION_TIMEOUT stops firing once negotiation begins is corrected the same way: the media bound stays armed past checking until ICE reaches connected or completed, so a connect stalling in between does report one. What never emits it is a viewer whose frames stop after it connected.

Paired with kernel-images#472, which holds the media bound at 10s so the budget fits. Merge order doesn't matter for the docs themselves, but the two describe the same client.

Docs only, prose and one snippet constant. I didn't run mint broken-links on this revision because mint isn't installed in this environment; the change touches no links and the check passed on the previous revision.