Element::rest() picked the keyframe with the largest gap to the next keyframe's
time. That reads a keyframe as a value held until the next one; it is the start
of a ramp toward it. A long gap after keyframe k means the screen spends that
time arriving at k+1, so the settled pose is at the far end of the gap.
The title wordmark zooms in over five frames and holds at (184,193) at 100% from
t=251 to t=264. The old rule picked the frame before the long gap: (179,186) at
101%, still mid-zoom.
Measured against the framebuffer capture of the running title screen, which is a
1:1 crop so frame coordinates map directly (confirmed: the copyright line lands
on row 669 in the capture and in both composites). Edge-correlated over the
wordmark box:
plateau (landed) best 0.4597 at shift (0,0)
longest dwell (old) best 0.1511 at shift (+3,+8), 0.1268 at (0,0)
The old composite scores 3x lower and only peaks after being moved, by about the
(-5,-7) that picking kf4 instead of kf5 predicts.
It also fixes six title elements the old rule rested at alpha 0x00 where the
capture plainly shows them, and pteff00.prm - the full-screen fade quad painted
last - which rested at opaque black. That was the blocker on .prm compositing.
Adds tools/re-capture/align_to_capture.py, which is how this was scored, and
turns the .prm test that deliberately asserted the old defect into a guard on
the fix.
Not settled and now the next item: compose ignores the keyframe fade alpha
entirely (blit modulates by tint only), which is why choosing the wrong keyframe
was invisible until now.
