tiny figure fixes

[mobeets]

• [x] Fig 1B: add output-null axis
• [x] Uncontrolled: keep in spikes view
• [x] Fig 1D: call this "new", not "learned"
• [x] Fig 1E: return to white, where you don't color in the full green ellipse
• [x] Uncontrolled/Habitual: make ellipses bigger so there's some sense of "the cloud"