Center the first-boot setup screen and fix its greeter animation

The setup progress screen stacked from row one while the greeter that precedes
it was already centered, so first boot changed shape between its two frames.
Center it on the same block height the ISO install dashboard uses — logo, blank,
title, blank, bar, blank, tip — and repaint it if the VT resizes, which is the
same virtio-gpu KMS handoff the greeter already watches for.

The greeter's ttfx call never passed --xterm-colors, so it hit exactly the
failure the comment above it describes: ttfx resolves even indexed stops to
truecolor, and the console reduces 256-colour codes well but 24-bit ones badly.
The gradient was being crushed rather than rendering as the indexed palette it
was written for, and the settle colour drifted off the green logo drawn beneath
it.

--canvas-width was cols-1 to stay off the autowrap column, which held for tte.
ttfx centres its text two columns right of plain centering, so cols-1 puts the
animated logo a column off the static one and it jumps when the effect starts.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

bin/omarchy-provision-owner

@@ -171,7 +171,11 @@ DARK="${CSI}90m"
 
 STATE_FILE=/run/omarchy-provision-owner.state
 FINALIZE_WARNING_FLAG=/run/omarchy-provision-owner.finalize-warning
+# Rows the setup screen occupies: logo, blank, title, blank, bar, blank, tip.
+SETUP_HEIGHT=$((LOGO_HEIGHT + 6))
+SETUP_TOP_ROW=1
 DYNAMIC_ROW=$((LOGO_HEIGHT + 3))
+LAST_SETUP_SIZE=""
 
 tips=(
   "Super + Space opens the Omarchy menu for apps, settings, and more"
@@ -201,6 +205,8 @@ term_cols() {
   printf '%s' "$cols"
 }
 
+term_size() { stty size 2>/dev/null </dev/tty || printf '24 80\n'; }
+
 # A fingerprint of the console geometry: the VT size plus the framebuffer's
 # identity and pixel size. On a fresh first boot the VT can come up in a
 # transitional ~80x25 mode and only widen to the real resolution a second or
@@ -381,14 +387,33 @@ setup_progress() {
   return 0
 }
 
+# Vertically center the setup block the way greeter_screen centers its splash,
+# so the screen the owner watches through finalization is composed rather than
+# stacked from row one — and first boot bookends the install identically.
+measure_setup_layout() {
+  local rows
+  LAST_SETUP_SIZE=$(term_size)
+  rows=${LAST_SETUP_SIZE%% *}
+  [[ $rows =~ ^[0-9]+$ ]] || rows=24
+  SETUP_TOP_ROW=$(((rows - SETUP_HEIGHT) / 2))
+  (( SETUP_TOP_ROW < 0 )) && SETUP_TOP_ROW=0
+  SETUP_TOP_ROW=$((SETUP_TOP_ROW + 1))
+  DYNAMIC_ROW=$((SETUP_TOP_ROW + LOGO_HEIGHT + 1))
+}
+
 render_setup_static() {
-  printf '%s%s' "$HIDE_CURSOR" "$CLEAR"
-  blank_line
+  measure_setup_layout
+  printf '%s%s%s%d;1H' "$HIDE_CURSOR" "$CLEAR" "$CSI" "$SETUP_TOP_ROW"
   render_logo
   blank_line
 }
 
 render_setup_dynamic() {
+  # The VT can still resize under us — the same virtio-gpu KMS handoff the
+  # greeter watches for. left_padding recomputes every frame, but the logo is
+  # drawn once, so repaint it at the new center rather than leaving the centered
+  # block stranded against a stale geometry.
+  [[ $(term_size) == "$LAST_SETUP_SIZE" ]] || render_setup_static
   set_now
   setup_progress
   printf '%s%d;1H' "$CSI" "$DYNAMIC_ROW"
@@ -470,18 +495,26 @@ greeter_screen() {
     # it never restarts — a restart is what flashed. The effect reads from
     # /dev/null so it never swallows the Return the foreground read waits on;
     # --reuse-canvas paints upward from the saved cursor, anchored one row below
-    # the logo to repaint exactly the rows drawn above. --canvas-width is cols-1
-    # to stay off the autowrap column.
+    # the logo to repaint exactly the rows drawn above.
+    #
+    # --xterm-colors is what actually keeps the palette indexed: ttfx resolves
+    # even indexed stops to truecolor otherwise, and the console reduces 256-colour
+    # codes well but 24-bit ones badly — that reduction is the muddy lavender.
+    # It also pins the settle colour to index 2, matching the green logo drawn
+    # above. --canvas-width is cols-2, not cols-1: ttfx centres its text two
+    # columns right of plain centering, so cols-1 lands the animated logo a
+    # column off the static one and it jumps when the effect starts.
     printf '%s%d;1H\0337' "$CSI" "$((logo_row + LOGO_HEIGHT))"
     # Run ttfx directly (not inside a `while` subshell) so $anim is ttfx's own
     # PID: killing a wrapping subshell would orphan ttfx, which then keeps
     # painting the logo over the keyboard step. --cycles is high enough that it
     # never ends on its own before Return.
     ttfx -i "$LOGO_PATH" \
-      --canvas-width "$((cols - 1))" \
+      --canvas-width "$((cols > 2 ? cols - 2 : cols))" \
       --anchor-text c \
       --frame-rate 60 \
       --reuse-canvas \
+      --xterm-colors \
       colorshift \
       --gradient-stops 2 10 6 10 \
       --gradient-frames 3 \