fix(studio): live-search exception, daemon-card width, featured tile size; add Start-hub button (v0.20.1)

Three reported bugs and one onramp gap:

- Store live-search threw `setState() callback returned a
  Future`. The `=>` body of `_runSearch` evaluated to the
  Future returned by `_load()`. Switched to a block body so
  the closure resolves to void; the future itself is still
  awaited by the FutureBuilder.

- Doctor's Daemon-control card was visibly narrower than its
  siblings — its only stretching child was a Wrap of small
  buttons. Wrapped the content in `SizedBox(width: infinity)`
  so the card fills the section's width like every other
  panel. Card now leads with the live `running on local:
  127.0.0.1:50051` status row + status pill so operators see
  state at a glance, then offers Restart / Start (when
  stopped) / Stop / Status.

- Featured tiles were 320×152 against the regular grid's
  ~360×168, so the editorial picks looked subordinate to
  the dense grid. Bumped to 480×220 with bigger icon, larger
  title, larger tagline so the strip reads as a hero band.

- ConnectionPill in the sidebar now offers an inline "Start
  hub" button when the daemon is unreachable. Spawns
  `fai daemon start` via SystemActions; the shell-level
  health poll picks the daemon up on its next tick. Closes
  the chicken-and-egg for Windows users who can't open a
  shell to bootstrap.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

pubspec.yaml

@@ -1,7 +1,7 @@
 name: fai_studio
 description: "F∆I Studio — desktop GUI for the F∆I hub"
 publish_to: 'none'
-version: 0.20.0
+version: 0.20.1
 
 environment:
   sdk: ^3.11.0-200.1.beta