Revert "Add Kiro IDE support (.kiro/) (#548)"

This reverts commit ce828c1c3c.

.kiro/steering/swift-patterns.md

@@ -1,67 +0,0 @@
----
-inclusion: fileMatch
-fileMatchPattern: "*.swift"
-description: Swift-specific patterns including protocol-oriented design, value types, actor pattern, and dependency injection
----
-
-# Swift Patterns
-
-> This file extends the common patterns with Swift specific content.
-
-## Protocol-Oriented Design
-
-Define small, focused protocols. Use protocol extensions for shared defaults:
-
-```swift
-protocol Repository: Sendable {
-    associatedtype Item: Identifiable & Sendable
-    func find(by id: Item.ID) async throws -> Item?
-    func save(_ item: Item) async throws
-}
-```
-
-## Value Types
-
-- Use structs for data transfer objects and models
-- Use enums with associated values to model distinct states:
-
-```swift
-enum LoadState<T: Sendable>: Sendable {
-    case idle
-    case loading
-    case loaded(T)
-    case failed(Error)
-}
-```
-
-## Actor Pattern
-
-Use actors for shared mutable state instead of locks or dispatch queues:
-
-```swift
-actor Cache<Key: Hashable & Sendable, Value: Sendable> {
-    private var storage: [Key: Value] = [:]
-
-    func get(_ key: Key) -> Value? { storage[key] }
-    func set(_ key: Key, value: Value) { storage[key] = value }
-}
-```
-
-## Dependency Injection
-
-Inject protocols with default parameters -- production uses defaults, tests inject mocks:
-
-```swift
-struct UserService {
-    private let repository: any UserRepository
-
-    init(repository: any UserRepository = DefaultUserRepository()) {
-        self.repository = repository
-    }
-}
-```
-
-## References
-
-See skill: `swift-actor-persistence` for actor-based persistence patterns.
-See skill: `swift-protocol-di-testing` for protocol-based DI and testing.