feat: add sealed blob v1 encryption/decryption

- Add sealed_blob.rs with encrypt/decrypt functions
- Update Cargo.toml with dependencies
- Regenerate Swift/Kotlin FFI bindings
- Update XCFramework for iOS
- Clean up documentation and archive old files

Author: JOHN

Cargo.lock

@@ -32,6 +32,9 @@ blake2 = "0.10"
 hkdf = "0.12"
 zeroize = "1"
 # Note: secrecy was removed - use zeroize::Zeroizing instead
+chacha20poly1305 = "0.10"
+base64 = "0.22"
+rand = "0.8"
 serde = { version = "1", features = ["derive"] }
 serde_bytes = "0.11"
 serde_json = "1"

Cargo.toml

@@ -5,7 +5,6 @@ Project documentation for `pubky-noise`.
 - **Integration guides**: Platform and app integration guidance.
 - **FFI guides**: UniFFI binding usage and operational notes.
 - **Release/migration**: Version-to-version breaking change guidance.
-- **Archive**: Older implementation reports kept for historical reference in `docs/archive/`.
 
 If you update public API behavior, update the relevant document(s) here and keep versions consistent with `Cargo.toml` and `CHANGELOG.md`.