We allow titlebarFont to be nil to differentiate between "system" (nil)
and "custom" (non-nil) behavior. For the "system" case, we need to use
the system _titlebar_ font (rather than just the default system font),
to match the system's conventions.
Fixes#1656
When called as part of window restoration AppKit has a lock, so
NSAppearance changes need to be called async.
See deadlock:
```
Thread 1 Queue : com.apple.main-thread (serial)
0 0x000000018fd63fac in __ulock_wait ()
1 0x00000001069bf720 in _dlock_wait ()
2 0x00000001069bfaec in _dispatch_group_wait_slow ()
3 0x0000000106b5f5c4 in interposed_dispatch_group_wait ()
4 0x00000001937fb1f0 in NSCGSTransactionRunPreCommitActions_ ()
5 0x00000001938f1230 in -[_NSCGSTransaction synchronize] ()
6 0x00000001938f11ac in NSCGSTransactionSynchronize ()
7 0x000000019382ad30 in +[NSCGSWindow(NSCGSSpace) isAnyWindowOnAVisibleSpace:] ()
8 0x000000019382a968 in -[NSWindow _isInSomeVisibleSpace] ()
9 0x000000019382a8e4 in -[NSWindow isOnActiveSpace] ()
10 0x0000000193db8d98 in -[NSApplication(NSApplicationAppearance_Internal) _invalidateWindowAppearances] ()
11 0x00000001938f44d4 in -[NSApplication(NSAppearanceCustomization) setAppearance:] ()
12 0x0000000102c48050 in AppDelegate.syncAppearance() at /Users/mitchellh/code/go/src/github.com/mitchellh/ghostty/macos/Sources/App/macOS/AppDelegate.swift:412
13 0x0000000102c47840 in AppDelegate.configDidReload(_:) at /Users/mitchellh/code/go/src/github.com/mitchellh/ghostty/macos/Sources/App/macOS/AppDelegate.swift:380
14 0x0000000102c43c7c in AppDelegate.applicationDidFinishLaunching(_:) at /Users/mitchellh/code/go/src/github.com/mitchellh/ghostty/macos/Sources/App/macOS/AppDelegate.swift:110
```
Add support for configurable fonts for window and tab titles. This is
only implemented for macOS (and could be macOS-only if other platforms
aren't able to support this using their windowing toolkits). It plays
nicely with regular and titlebar tabs.
Previously files would be pasted as only the filename. This commit
introduces an extension to NSPasteboard which provides a method to
consistently get the string contents of a pasteboard so that the
behavior can stay the same anywhere where we need to do that.
To do this I forced a toolbar, so that we would have a place to put the
button when no tabs were opened. I also took the opportunity to make the
standard title/tab bar meld better with the terminal's background color,
just as we do with titlebar tabs.
Fixes#1500
This overhauls how we do focus management for surfaces to make it more
robust. This DID somehow all work before but was always brittle and was
a sketchy play with SwiftUI/AppKit behavior across macOS versions.
The new approach uses our window controller and terminal delegate
system to disseminate focus information whenever any surface changes
focus. This ensures that only ONE surface ever has focus in libghostty
because the controller ensures it is widely distributed.