Hands: step mode and pose pictures for the hand recorder

The first real session moved on every 5 s with text only, too fast to follow.
Each step now waits for Next (Space or the window's button), counts down 3-2-1
while recording, then holds. P pauses, R redoes a step, S skips a section;
"Advance by itself" (--auto) keeps the old timed flow. Nothing records while
a step waits: each step is its own recording part.

The panel and the window show a picture of each pose (hands/rec/poses,
generated by make_poses.py from a parametric hand, MIT) and a diagram of where
to hold the hands and how far out. prompts.jsonl gains ready, wait and redo
events; session.json gains mode.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

hands/rec/poses/poses.json

@@ -0,0 +1,182 @@
+{
+  "flat": {
+    "file": "flat.png",
+    "two_hands": false,
+    "caption": "Palm toward you, fingers together"
+  },
+  "flat-back": {
+    "file": "flat-back.png",
+    "two_hands": false,
+    "caption": "Back of the hand toward you"
+  },
+  "spread": {
+    "file": "spread.png",
+    "two_hands": false,
+    "caption": "Fingers spread wide"
+  },
+  "open": {
+    "file": "open.png",
+    "two_hands": false,
+    "caption": "Open and relaxed"
+  },
+  "fist": {
+    "file": "fist.png",
+    "two_hands": false,
+    "caption": "A fist"
+  },
+  "point": {
+    "file": "point.png",
+    "two_hands": false,
+    "caption": "Point with your index finger"
+  },
+  "pinch": {
+    "file": "pinch.png",
+    "two_hands": false,
+    "caption": "Thumb and index tips touching"
+  },
+  "ok": {
+    "file": "ok.png",
+    "two_hands": false,
+    "caption": "OK sign: a ring, three fingers up"
+  },
+  "thumbs-up": {
+    "file": "thumbs-up.png",
+    "two_hands": false,
+    "caption": "Thumbs up"
+  },
+  "claw": {
+    "file": "claw.png",
+    "two_hands": false,
+    "caption": "Fingers curled like a claw"
+  },
+  "count-1": {
+    "file": "count-1.png",
+    "two_hands": false,
+    "caption": "One: index finger"
+  },
+  "count-2": {
+    "file": "count-2.png",
+    "two_hands": false,
+    "caption": "Two: index and middle"
+  },
+  "count-3": {
+    "file": "count-3.png",
+    "two_hands": false,
+    "caption": "Three: index, middle, ring"
+  },
+  "count-4": {
+    "file": "count-4.png",
+    "two_hands": false,
+    "caption": "Four: thumb folded in"
+  },
+  "count-5": {
+    "file": "count-5.png",
+    "two_hands": false,
+    "caption": "Five: all fingers spread"
+  },
+  "turn-in-out": {
+    "file": "turn-in-out.png",
+    "two_hands": false,
+    "caption": "Turn your wrist: palm in, palm out"
+  },
+  "turn-up-down": {
+    "file": "turn-up-down.png",
+    "two_hands": false,
+    "caption": "Palm down, turn it up, then back"
+  },
+  "bend": {
+    "file": "bend.png",
+    "two_hands": false,
+    "caption": "Bend your wrist up, down, side to side"
+  },
+  "pinch-tap": {
+    "file": "pinch-tap.png",
+    "two_hands": false,
+    "caption": "Tap thumb and index together"
+  },
+  "pinch-drag": {
+    "file": "pinch-drag.png",
+    "two_hands": false,
+    "caption": "Pinch, move to the side, let go"
+  },
+  "grab": {
+    "file": "grab.png",
+    "two_hands": false,
+    "caption": "Close your hand around a bar, open it"
+  },
+  "open-close": {
+    "file": "open-close.png",
+    "two_hands": false,
+    "caption": "Open and close your hand"
+  },
+  "cross": {
+    "file": "cross.png",
+    "two_hands": true,
+    "caption": "Cross your hands, then uncross"
+  },
+  "overlap": {
+    "file": "overlap.png",
+    "two_hands": true,
+    "caption": "One hand over the other, slide around"
+  },
+  "near-face": {
+    "file": "near-face.png",
+    "two_hands": true,
+    "caption": "Hands near your face, not touching"
+  },
+  "screen-point": {
+    "file": "screen-point.png",
+    "two_hands": false,
+    "caption": "Point at a screen at arm's length"
+  },
+  "typing": {
+    "file": "typing.png",
+    "two_hands": true,
+    "caption": "Type on the keyboard"
+  },
+  "lift": {
+    "file": "lift.png",
+    "two_hands": true,
+    "caption": "Lift your hands off the keyboard, put them back"
+  },
+  "mouse": {
+    "file": "mouse.png",
+    "two_hands": false,
+    "caption": "Hand on the mouse, move and click"
+  },
+  "switch": {
+    "file": "switch.png",
+    "two_hands": true,
+    "caption": "Switch between keyboard and mouse"
+  },
+  "hold": {
+    "file": "hold.png",
+    "two_hands": true,
+    "caption": "Pick it up, use it, put it down"
+  },
+  "push": {
+    "file": "push.png",
+    "two_hands": false,
+    "caption": "Palms out, push out and back"
+  },
+  "push-controller": {
+    "file": "push-controller.png",
+    "two_hands": false,
+    "caption": "Controller on, push out and back"
+  },
+  "touch-stick": {
+    "file": "touch-stick.png",
+    "two_hands": true,
+    "caption": "Touch the thumbstick with your other index"
+  },
+  "touch-stick-desk": {
+    "file": "touch-stick-desk.png",
+    "two_hands": true,
+    "caption": "Touch the thumbstick of the controller on the desk"
+  },
+  "no-hands": {
+    "file": "no-hands.png",
+    "two_hands": false,
+    "caption": "Hands down, out of view"
+  }
+}