refactor: reorganize Examples directory structure

- Move MistDemo to standalone package structure (Examples/MistDemo/)
- Create Package.swift for MistDemo (consistent with Celestra)
- Add Celestra RSS reader example demonstrating query filtering
- Add CloudKitService+RecordModification for public record operations
- Remove top-level Examples/Package.swift (each example is now independent)

Both demo projects now have consistent structure:
- Examples/Celestra/ - RSS reader with filtering/sorting
- Examples/MistDemo/ - Web auth demo with Hummingbird

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: leogdion

Examples/Celestra/.env.example

@@ -0,0 +1,14 @@
+# CloudKit Configuration
+# Copy this file to .env and fill in your values
+
+# Your CloudKit container ID (e.g., iCloud.com.example.Celestra)
+CLOUDKIT_CONTAINER_ID=iCloud.com.example.Celestra
+
+# Your CloudKit server-to-server key ID from Apple Developer Console
+CLOUDKIT_KEY_ID=your-key-id-here
+
+# Path to your CloudKit private key PEM file
+CLOUDKIT_PRIVATE_KEY_PATH=/path/to/eckey.pem
+
+# CloudKit environment: development or production
+CLOUDKIT_ENVIRONMENT=development

Examples/Celestra/Package.resolved

@@ -0,0 +1,25 @@
+// swift-tools-version: 5.9
+import PackageDescription
+
+let package = Package(
+    name: "Celestra",
+    platforms: [.macOS(.v14)],
+    products: [
+        .executable(name: "celestra", targets: ["Celestra"])
+    ],
+    dependencies: [
+        .package(path: "../.."),  // MistKit
+        .package(url: "https://github.com/brightdigit/SyndiKit.git", from: "0.6.0"),
+        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.5.0")
+    ],
+    targets: [
+        .executableTarget(
+            name: "Celestra",
+            dependencies: [
+                .product(name: "MistKit", package: "MistKit"),
+                .product(name: "SyndiKit", package: "SyndiKit"),
+                .product(name: "ArgumentParser", package: "swift-argument-parser")
+            ]
+        )
+    ]
+)