fix(app): turn off question dock animation by default - #59389

The question dock no longer animates. Switching questions, minimizing, restoring and submitting now change on the same frame.
The new dock, keyboard answering, number keys, the "N of M" title, the dashes and the Back/Next/Submit footer all stay. The old motion is still available behind one Knobs toggle, Timeline → Question → Question dock motion, which is off by default.

❌ Before

1. Press → or Next.
2. ❌ The dock blurs out a copy of the old question, springs to the new height, rolls the number and slides the progress bar along.
3. ❌ Minimize, restore and submit each play their own fold, grow or exit.

✅ After

1. Press → or Next.
2. The next question, its number and its lit dash appear on the next frame, already at their final size.
3. Minimize, restore and submit fold, unfold or swap in the composer at once.

- switch question -> ghost copy + blur + height spring + rolling number + sliding bar
+ switch question -> if motion knob on: same as before, else paint the new question once
- minimize / restore / submit -> fold, grow and exit animations
+ minimize / restore / submit -> instant unless the motion knob is on

📊 Proof

The new test, "switches questions, folds and submits on the same frame with the dock's motion off", fails on dev and passes here. The existing motion tests now turn the knob on first and still pass, as do the keyboard tests from #58494 and #59333.

Knob off: switching with the keys and a click, minimize, restore, then submit.

Visual

<svg xmlns="http://www.w3.org/2000/svg" width="240" height="72" viewBox="0 0 240 72" fill="none">
  <rect x="8.5" y="6.5" width="223" height="59" rx="8" stroke="currentColor" stroke-opacity=".25"/>
  <rect x="20" y="16" width="34" height="4" rx="2" fill="currentColor" fill-opacity=".35"/>
  <g fill="currentColor">
    <rect x="160" y="17" width="10" height="2" rx="1" fill-opacity=".2"/>
    <rect x="174" y="17" width="10" height="2" rx="1" fill-opacity=".2"/>
    <rect x="188" y="17" width="10" height="2" rx="1" fill-opacity=".2"/>
    <rect x="202" y="17" width="10" height="2" rx="1" fill-opacity=".2"/>
    <rect y="17" width="10" height="2" rx="1" x="160">
      <animate attributeName="x" values="160;174;188;202;160" keyTimes="0;.25;.5;.75;1" dur="4s" calcMode="discrete" repeatCount="indefinite"/>
    </rect>
  </g>
  <g fill="currentColor" fill-opacity=".55">
    <rect x="20" y="28" width="120" height="4" rx="2">
      <animate attributeName="width" values="120;96;140;84;120" keyTimes="0;.25;.5;.75;1" dur="4s" calcMode="discrete" repeatCount="indefinite"/>
    </rect>
  </g>
  <g fill="currentColor" fill-opacity=".25">
    <rect x="20" y="40" width="80" height="3" rx="1.5"/>
    <rect x="20" y="50" width="64" height="3" rx="1.5"/>
  </g>
  <rect x="176" y="44" width="44" height="14" rx="4" stroke="currentColor" stroke-opacity=".4"/>
  <rect x="188" y="50" width="20" height="2" rx="1" fill="currentColor" fill-opacity=".5"/>
</svg>

👀 Read: session-question-dock.tsx, the new still() path: with the knob off, wake() snaps every spring, drops the outgoing copy and paints once instead of starting a frame loop, and the boxes keep their natural heights. spring-height.tsx gains an instant option so the composer swap and the dock's grow skip their morph for the question dock only. The CSS only scopes the existing transitions under data-animated="true". The rest is routine.

_{🔍 Asked for in team chat · the motion stays available behind the Question dock motion knob}