Release v0.3.0

[shellrow]

Summary

• Hardened the E2EE core, replay handling, key lifecycle, protocol limits, and secret redaction behavior.
• Added HTTP protected-context support across core, axum, Workers, streaming bodies, selected-header binding, key rotation, and durable replay stores.
• Added datagram and message transport support, including QUIC datagrams, raw UDP, WebSocket, browser WebSocket, WebTransport datagrams, and cross-shape conformance coverage.
• Expanded the WASM/TypeScript SDK with body envelopes, framed sessions, datagram mode, in-session rekey, browser runtime tests, and HTTP protected-context bindings.
• Added record-bound storage envelopes and guidance for zero-knowledge storage backends.
• Expanded examples, two-process integration tests, browser interop tests, fuzz targets, canonical vectors, independent vector verification, Miri, and CI gates.
• Updated the spec, threat model, operational policies, deployment guidance, test runbook, and changelog.