Remove pre-WinUI 3 root-level dead code (#49)

These files are leftovers from the Win32 + GhosttyBridge singleton host
that predated the WinUI 3 + TabView shell. None of them are referenced
by any project in GhosttyWin32.slnx (GhosttyTests, GhosttyWin32 (Package),
GhosttyWin32App):

- GhosttyBridge.cpp / .h — old singleton bridge; superseded by
  GhosttyWin32App/GhosttyApp + Tab + TerminalControl.
- GhosttyWin32.h — only included resource.h; nothing else included it.
- GhosttyWin32.rc / Resource.h — Win32 RC resources for the old Win32
  exe; no project compiles them anymore.
- GhosttyWin32.ico / small.ico — referenced only from the .rc above.
  Package tile / store logo uses Images\StoreLogo.png from the .wapproj.

Removing them so future contributors (and grep) don't get misled into
treating GhosttyBridge as live code.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Release candidate 1 for v0.3.0

CI: remove scoop dispatch trigger (handled by scoop-release-ci)

CI: remove scoop dispatch trigger (handled by scoop-release-ci)

CI: auto-create scoop-bucket PR on release

After release is created, automatically:
1. Calculate SHA256 hash of the zip
2. Clone scoop-bucket
3. Update ghosttywin32.json via jq
4. Create PR to scoop-bucket

Requires SCOOP_TOKEN secret with repo scope.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Fix CI: copy ghostty.h from fork