port: F5 -- (A) during the title build-in snaps the ONE shared clock to the settle

Measured by the Decoder: the plate reaches alpha 255 in a single frame against
~11 frames of ramp with no input, and the sweep enters at 255 with no ramp where
an untouched run obeys its parent's declared t=70..100 gate. A cut, not an
acceleration.

It advances the ONE SHARED CLOCK, so authored/flow.json's clock: 'shared' stands.

🔴 I IMPLEMENTED THE OPPOSITE FIRST AND REVERTED IT. Their initial report had the
artwork animating across the press, which would mean two clocks and an
overlay-only jump; I built that (_plate_offset). It rested on a 5-frame window
that sat entirely inside the 11-12 frame lag between a scripted press and its
effect -- it compared frames where the input had not been acted on yet. A wider
pre-registered test refuted it: three elements mid-fade vanish in one frame.

🔴 AND MY FIRST VERSION NEVER FIRED, SILENTLY. It gated on overlay.settle_instant,
which is -1 for press_start: that screen declares a 22-unit settle window against
SETTLE_WINDOW_MIN=30. The boot has always printed 'settles at t=236' from
settle_time(), a DIFFERENT quantity, and I took the printed number as evidence
for the field I was testing. Caught only by filming and seeing overlay-view stay
flat at 0.0 across the press.

⚠️ The target is BOUNDED, not pinned: the capture puts it inside [100,238] -- past
the sweep's gate at 100, not past 250 or ptloop01's exit ramp would return the
sweep to alpha 0. settle_time()=236 sits inside that and is where the plate
reaches full alpha.

New diagnostic --press-at=S[,S...] presses (A) at wall-clock moments anywhere in
a boot; --skip-at lives inside the movie branch and fires once, so it cannot
reach the title. Marked fragile by construction.

VERIFIED on a filmed boot: shared clock jumps 109.4 -> 236.0 and view_units and
overlay_units move together across the press.

port/scripts/boot.gd

@@ -180,6 +180,18 @@ func _ready() -> void:
 	if args.has("script"):
 		_script = args["script"].split(",", false)
 	_skip_at = float(args.get("skip-at", "0"))
+	# `--press-at=S[,S…]` presses Ⓐ at wall-clock moments ANYWHERE in a boot.
+	# `--skip-at` cannot do it: it lives inside the movie branch and fires once,
+	# so it can skip the intro and nothing after. Needed to exercise the second
+	# of the three Ⓐ presses (the plate snap), which lands on the title.
+	#
+	# ⚠️ Wall-clock, and therefore fragile by construction -- the Decoder found
+	# blind delays cannot reliably hit a window when pacing varies. It is a
+	# DIAGNOSTIC for a deterministic local boot, not an instrument to assert with.
+	if args.has("press-at"):
+		for part in String(args["press-at"]).split(",", false):
+			_press_at.append(float(part))
+		_press_at.sort()
 	# `--focus=<element id>` draws a button's focus record in a `--screen` run,
 	# which otherwise focuses nothing. A diagnostic: the spinning ring is only
 	# drawn on a FOCUSED button, so without this the ring can only be observed in
@@ -487,6 +499,9 @@ var _black_hold := 0.0
 ## `--focus=<id>`: draw this element's focus record in a `--screen` run.
 var _force_focus := ""
 var _skip_sent := false
+
+## Pending `--press-at` moments, ascending. See where it is parsed.
+var _press_at: Array = []
 var _script_started := false
 var _sequence: Array[Dictionary] = []
 var _player: VideoStreamPlayer = null
@@ -560,6 +575,10 @@ func _process(delta: float) -> void:
 	_screen_frames += 1
 	_worst_gap = maxf(_worst_gap, delta)
 	view.queue_redraw()
+	while not _press_at.is_empty() and _elapsed >= float(_press_at[0]):
+		_press_at.pop_front()
+		print("     --press-at: pressing (A) at %.2f s" % _elapsed)
+		_press("ui_accept")
 	_overlay_process(delta)
 	_menu_repeat(delta)
 
@@ -942,6 +961,45 @@ func _unhandled_input(event: InputEvent) -> void:
 			_player.stop()
 			_video_finished()
 		return
+	# F5, MEASURED: Ⓐ during the title's build-in is a CUT, not an acceleration.
+	# The plate goes to alpha 255 in ONE frame against about eleven frames of ramp
+	# with no input, and the sweep enters at 255 with no ramp at all where an
+	# untouched run takes its parent's declared `t=70…100` gate
+	# (`docs/re/f5-a-press-snaps-the-plate.md`).
+	#
+	# 📌 IT ADVANCES THE ONE SHARED CLOCK, which is why `authored/flow.json`'s
+	# `clock: "shared"` stands. Both agents briefly had the opposite: a first pass
+	# reported the artwork animating across the press, which would have meant two
+	# clocks and an overlay-only jump. That rested on a 5-frame window which sat
+	# entirely inside the 11-12 frame lag between a scripted press and its effect,
+	# so it compared frames where the input had not been acted on yet. A wider
+	# pre-registered test refuted it: three elements mid-fade vanish in a single
+	# frame. I had implemented the overlay-only version; it is reverted here.
+	#
+	# ⚠️ The target is BOUNDED, not pinned. The capture puts it inside [100, 238]
+	# -- past the sweep's gate at 100, and not past 250 or `ptloop01`'s exit ramp
+	# would have taken the sweep back to alpha 0. `settle_time()` is 236 for this
+	# overlay, which is inside that bound and is where the plate reaches full
+	# alpha. If the game turns out to snap somewhere else in the window, this is
+	# the line to move and nothing else changes.
+	#
+	# 🔴 NOT `settle_instant`: the first version of this used it and NEVER FIRED,
+	# silently. `press_start` declares a 22-unit settle window against a 30-unit
+	# minimum, so `settle_instant` is -1 for this screen. The boot has always
+	# printed "settles at t=236" from `settle_time()`, a different quantity, and I
+	# read the printed number as evidence for the field I was testing.
+	#
+	# It is the SECOND of three presses from the logos to the menu -- skip movie,
+	# reveal plate, activate it. Consuming the press keeps the second and third
+	# distinct.
+	if overlay != null and event.is_action_pressed("ui_accept"):
+		var snap_to := overlay.settle_time()
+		if snap_to > 0.0 and view.time_units < snap_to:
+			print("  (A) snaps the title: shared clock %.1f -> %.1f" % [view.time_units, snap_to])
+			view.time_units = snap_to
+			view.queue_redraw()
+			_overlay_process(0.0)
+			return
 	if _menu == null or _menu.stack.is_empty():
 		return
 	# AUTHORED, not measured: a press during a screen's fade-out is dropped.