ReaServe v0.1.2

Added

• REAPER ExtState API bindings (SetExtState, GetExtState, HasExtState, DeleteExtState).
• Go integration test suite (tests/integration/reaserve_test.go) that exercises every method in PROTOCOL.md against a live REAPER instance. Uses //go:build integration tag so it is never picked up by normal go test runs.
• Makefile with targets: release, debug, test, test-integration, install, clean, rebuild, help.
• make install auto-detects REAPER UserPlugins path per platform (Linux/macOS/Windows).

Changed

• Breaking: lua.execute_and_read no longer requires state_path parameter. Lua code must now call reaserve_output(json_string) to return data instead of writing to a file. The file-based result passing mechanism has been replaced with REAPER's in-memory ExtState API (SetExtState/GetExtState).
• User Lua code in lua.execute_and_read is now wrapped in pcall() — Lua runtime errors are captured and returned in the JSON-RPC error response instead of being silently swallowed.
• Updated PROTOCOL.md to reflect new lua.execute_and_read interface and document reaserve_output().