Animate the restart figure, and pin down the path matching

[marcosqlbi]

Two things, and one of them is a correction.

The figure now moves

Pick up where you left off was the only figure on the page that sat still. It now uses the
same staggered fig-pop as f4, f8 and f10 — same 6.5s cycle, same 0 / .3 / .6 delays:

1. the board as you left it,
2. the restart arrow,
3. the board again.

So the second window arriving after the first is the thing the eye follows. It rests on both
windows for most of the loop, per the comment at the top of that CSS block, and inherits the
existing is-visible observer and the prefers-reduced-motion gate without touching either.

The short-path limitation does not exist

I reported that IsSameFile would miss a match between C:\Users\MARCOR~1\board.wboard and
C:\Users\MarcoRusso\board.wboard. That was wrong. Path.GetFullPath expands 8.3
components against the directory entries, so the original code already handled it.

I found out by writing the fix: a GetLongPathName interop went in, and the new test passed
just as well with it disabled. Deriving a real short path with GetShortPathName and printing
what GetFullPath returns settled it — the long form comes back. The interop is removed; it
did nothing.

What survives is the part that has value:

• IsSameFile moves from MainWindow to SessionStore, where the smoke tests can reach
  it. That move is what made the question answerable instead of arguable.
• A smoke test covers it, deriving a genuine 8.3 path at run time rather than asserting
  against a hand-written one. It also covers case differences and a redundant path component.
  On a volume with 8.3 names turned off it degrades to comparing a path with itself rather
  than failing.
• The remark on IsSameFile records why it is correct and the one condition it rests on:
  the expansion needs the file to be there to read. That holds here, since the board being
  opened exists and the slot that matches it names that same file.

No version bump

VersionPrefix stays at 1.5.0. Nothing here changes what the application does — a refactor,
a test, and a site figure. Say the word if you want 1.5.1 anyway and I will add it with an
honest entry.

Both smoke harnesses pass; the figure checked in light and dark, and frame-sampled mid-cycle
to confirm the order.

🤖 Generated with Claude Code