[kitlangton]

The capsule playground now shows the recording pill's candidate motions side by side, drawn by Hex itself.
A new "Pill motion" section lines up how the pill could come in, rest while you're silent, and finish into the Undo receipt. It's a playground prototype only: the real capsule moves as it does today.

💡 Why
The web mockups couldn't show these on the real voice-reactive dot field, so it was hard to judge them. This draws them inside Hex's own renderer, over the real Dot scope simulation, with a scripted voice that goes silent, speaks, then goes silent again.

🆕 Now you can

• Open hex capsule-playground and pick Entrance, Silence or Finish under "Pill motion".
• Compare the entrance options, today's scale and fade and a draw-on that lights the dot and sweeps the field in.
• Compare four silences: today's dots, a flat line, a line that spreads from the centre, and beads.
• Compare three finishes: today's, one thread that becomes the Undo timer and flies into the ✓, and a fold up under the menu bar.
• Render any of them as a clip with --video … --scene motion-entrance|motion-silence|motion-finish.

🚦 How it ships
Only in the playground, which is hidden and only in capture builds. Release behaviour is unchanged until one is picked. Reduce Motion is respected: springs become short fades and shape changes land at once.

  playground stage = real capsule
+ playground stage = real capsule, or one section's options in stacked lanes,
+                    each frame drawn from one clock (so a clip is exact)
+ dot field: optional per-column "flatness" that lays the traces on the middle row

📊 Proof

Entrance (Now, E3 · Draw on):

entrance-1x.mp4

Silence (I1 dots, I2 flat line, I3 from the centre, I4 beads):

silence-1x.mp4

Finish (Now, F1 · One thread, F2 · Fold away):

finish-1x.mp4

Rendered at 240 fps with Hex's own headless clip renderer, dark theme, then checked frame by frame for pops, seams and jumps. Frame-to-frame change per lane shows no spikes other than video keyframes. One remaining: a 2 pt dip in "Fold away" still moves its text a pixel at a time, which you can't see at normal speed.

👀 Read: playground/motion.rs, where everything is drawn from the clock. It copies the capsule's shell look instead of reusing it, which is fine for a throwaway prototype. The dot field's new flatness setting is off unless something sets it, and the existing scope tests pass unchanged. The rest is routine.

_{Requested on the board after the web mockups · no user reports · clips rendered headless on a Mac}

Checks run

• cargo test --locked --bin hex -- capture_capsule dot_scope: 150 passed
• cargo clippy --locked --bin hex --tests: clean (after one fix)
• cargo fmt --check, git diff --check: clean