v0.25.0: detachable sessions mirror inline images

Upgrade note: the attach socket protocol goes from 1 to 2 — update
shellglass push --detachable and shellglass attach together. They are
shipped as separate binaries, so a skewed attach is now refused with an
explicit reason instead of failing halfway through the handshake. Nothing
else moves: the push wire protocol stays at 2 (no coordinated hub/pusher
update), and session keys, ids and view URLs are unaffected.

Detachable push sessions mirror inline images. Until now push --detachable
dropped kitty/iTerm2/sixel graphics, because a terminal-less session has no
terminal to probe for image capabilities. An attach now hands the session its
terminal profile — graphics capabilities, default foreground/background, and
cell geometry — which the session caches: images keep being intercepted,
decoded and mirrored after you detach, using the last attached terminal's
profile, and that terminal's dimensions are retained as before. A later
attach replaces the cached profile only once its own capability probe
succeeds, so a failed or skewed attach never degrades a running session;
before the first successful attach, graphics interception stays disabled.
While detached, a kitty capability query is answered from the cached profile
(file/shm queries are still refused, as on the local mirror). --sixel-compat
now applies to detachable sessions too.

Windows keeps its native mouse gestures. shellglass no longer clears the
console's Quick Edit bit for the whole run, so under Windows Terminal wheel
scrollback and right-click paste keep working while you use an ordinary
shell. Quick Edit is released only while the mirrored program has explicitly
enabled an xterm mouse-reporting protocol, and restored when it stops.

The vendored vt100 recognizes two more mouse encodings: urxvt (1015) and
SGR with pixel coordinates (1016), alongside the existing 1005/1006. A TUI
selecting one is now correctly seen as having mouse reporting enabled —
which is what the Windows Quick Edit handoff keys off.