Refactor __init__.py with imports and versioning

Updated module docstring and added imports for secure messaging components.

Author: BryceWDesign

src/cyphersyntax/__init__.py

@@ -1,3 +1,48 @@
-"""CypherSyntax secure messaging core."""
+"""Authenticated secure-messaging primitives for CypherSyntax."""
 
-__all__: list[str] = []
+from .errors import (
+    CypherSyntaxError,
+    EnvelopeError,
+    HandshakeError,
+    IdentityError,
+    InvalidSignatureError,
+    KeyConfirmationError,
+    PersistenceError,
+    ReplayDetectedError,
+    StoreError,
+)
+from .handshake import HandshakeConfirmation, HandshakeOffer, HandshakeResponse
+from .identity import Identity
+from .session import (
+    AeadSuite,
+    InitiatorHandshake,
+    ResponderHandshake,
+    SessionFactory,
+    SessionState,
+)
+from .store import EncryptedStore
+
+__version__ = "0.1.0"
+
+__all__ = [
+    "AeadSuite",
+    "CypherSyntaxError",
+    "EncryptedStore",
+    "EnvelopeError",
+    "HandshakeConfirmation",
+    "HandshakeError",
+    "HandshakeOffer",
+    "HandshakeResponse",
+    "Identity",
+    "IdentityError",
+    "InitiatorHandshake",
+    "InvalidSignatureError",
+    "KeyConfirmationError",
+    "PersistenceError",
+    "ReplayDetectedError",
+    "ResponderHandshake",
+    "SessionFactory",
+    "SessionState",
+    "StoreError",
+    "__version__",
+]