🐞 main doesn't build with Xcode 27 #2197

Description

I'm getting set up to contribute, and main doesn't build with Xcode 27. I ran into three problems:

1. Ambiguous opacity in EditorTabsOverflowShadow.swift:

   EditorTabsOverflowShadow.swift:38:18: error: ambiguous use of 'opacity'
   

   Switching .background(...) to the closure form, .background { ... }, fixes it.

2. @State set before init in KeyValueTable.swift:

   KeyValueTable.swift:40:9: error: variable 'self.keyColumnName' used before being initialized
   KeyValueTable.swift:41:9: error: variable 'self.keyColumnName' used before being initialized
   

   The initializer assigns self.key and self.value (both @State) before the other stored properties are set. Initializing the wrappers directly fixes it: self._key = State(initialValue: key ?? ""), and the same for value.

3. SwiftLint plugin errors. Every build prints The folder “Output” doesn’t exist. once for each of the 6 SwiftLint plugin runs, and lists all 6 under "The following build commands failed". This one doesn't actually break anything: lint still runs, and the build still succeeds. It comes from lukepistrol/SwiftLintPlugin (we're on 0.59.1), which declares an Output folder that SwiftLint never creates. The latest release (0.65.0) still has the same line. It also isn't new in Xcode 27: Stabilize Project Navigator UI tests #2183 mentions the same messages with Xcode 26.6.

I'd like to fix 1 and 2 in a small PR, if that's ok. Both are tiny changes that shouldn't change any behavior.

I'm leaving 3 alone because the fix is in a third-party plugin, so it seems like something for a maintainer to decide. A few options I can see: leave it as is, report it to the plugin, or move to SwiftLint's own plugin package (SimplyDanny/SwiftLintPlugins). I'm happy to help with whichever you choose.

To Reproduce

1. Install Xcode 27.2.
2. Clone main.
3. Build in Xcode, or run:

   xcodebuild -scheme CodeEdit -destination "platform=macOS,arch=arm64" -skipPackagePluginValidation build
   

4. See the errors above.

Expected Behavior

main builds with Xcode 27 without errors.

Version Information

CodeEdit: main at fa2aebd
macOS: 27.2
Xcode: 27.2 (27B52)