N7 won't boot after failed Kit Kat upgrade
i recently got a notification for the Kit Kat upgrade on my Nexus 7. i tried to apply the upgrade but it failed (see attached image). when it rebooted afterwards, i could see the new Kit Kat splash/loading screen (the green + blue + yellow + red droplets coming together), but it never progress beyond that point (that screen will run until the battery drains).
i'm not quite sure how to recover from this, and the worst part is that i have pictures stored locally on the device that i'd _really_ like to keep (a running diary of a daily picture i'd taken for over 150 consecutive days).
1) is there any way to recover my pictures?, and...
2) how can i restore my device (or preferably, upgrade to Kit Kat).
fwiw - Clockworkdmod is installed.