port: add --leaf-time, and the title's residual is the sweep phase (~400 units, not 357.7)

The Decoder's refined sweep fit had never been testable: verify-capture passed
it as a whole-screen --time that pose_at discarded, and asking for it honestly
poses past the title's group end. --leaf-time separates the leaf's clock from
the screen's.

Controls: the renderer is deterministic (3 runs bit-identical) and the sweeps
move 0.40% of the frame between phases, so the comparison can see them.

Sweeping the full 600-unit span gives a sharp basin at 390-415 units (0.0124%)
against 0.2532% at t=357.7 -- 20x. So the title's 0.21% residual is the sweep
phase, not structure: at the fitted phase it matches the capture as well as the
splashes do.

NOT adopted: the port loops the leaf freely and re-posing the harness to the
fitted value would be tuning until they match. Filed instead, with the question
of whether 357.7 and this are even the same quantity.

Also verified last iteration's settle-window change was surgical: only
press_start and its twin moved, 14 screens unchanged including title's
Decoder-confirmed [160,236]. Settle-window ties exist on 4 screens but all sit
under the 30-unit bar, so the arbitrary tie-break never reaches the runtime.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF

tools/port/verify-capture

@@ -135,7 +135,7 @@ for row in "${MAP[@]}"; do
   note=""
   case "$name" in
     main_menu|extras) note="rendered with authored initial focus" ;;
-    title) note="posed at the SETTLE (t=198); see the note in this file" ;;
+    title) note="settle t=198; residual is the SWEEP PHASE -- see DECISIONS.md" ;;
   esac
   # Where the difference lives. This comes FIRST because it is what the gamma
   # sweep has to be protected from.