Release v0.2.0

Highlights

• Runtime-cost and connection-lifecycle release: native gRPC transport mode (−47% memory per RPC), server keepalive on by default (dead peers reclaimed automatically), and a complete client keepalive + reconnection story.

Added

• WithNativeGRPCTransport / BridgeConfig.ShouldUseNativeGRPCTransport — serves tunneled sessions through grpc.Server.Serve and gRPC's native HTTP/2 transport instead of the net/http handler path: 9.2 KB / 163 allocs per unary RPC vs 17.3 KB / 228 (−47% bytes, −28% allocs), ~20% faster server-stream drains, native flow control, and gRPC server keepalive support. Tradeoffs (no upgrade-header forwarding; no transport credentials on the grpc.Server) are documented. Verified for unary, server-streaming, and bidirectional RPCs plus concurrent clients.
• WithTunnelKeepalive / TunnelConfig.KeepaliveConfig / ApplyTunnelKeepalivePolicy — client-side gRPC keepalive over the tunnel (native and WASM builds): detects silently dead connections (NAT resets, dropped networks) and triggers automatic reconnection even with no active streams.
• WithKeepaliveDisabled / BridgeConfig.ShouldDisableKeepalive — explicit opt-out of server keepalive probing.
• docs/core/CONNECTION_LIFECYCLE.md — authoritative connect/disconnect/timeout/reconnect guide: keepalive matrix, disconnect-detection paths, reconnection tuning, browser caveats, recommended production configuration, and transport-mode comparison.
• Lifecycle test suite: dead-peer reclamation, server-restart reconnection (WaitForReady), keepalive defaulting rules, native-transport end-to-end and concurrency tests, and transport-mode benchmarks.

Changed

• Server keepalive defaults on (30s ping / 120s idle) when not explicitly configured — silently dead clients previously pinned connection slots and goroutines until the OS TCP timeout. Disable with WithKeepaliveDisabled() when an upstream boundary owns liveness.
• Handler-mode serving drops the redundant h2c upgrade shim (requests inside ServeConn are already HTTP/2), removing a per-request indirection.
• CI: bumped playwright-go to v0.6000.0 — the 1.52 driver's playwright.azureedge.net CDN was retired and returned 404s, breaking every e2e lane.