Initial public release v0.0.1.alpha2

opencode-rails — production-grade Rails integration for OpenCode.

Rails companion to opencode-ruby. ActiveRecord-aware session lifecycle
(idempotent ensure!/recreate!/abort! with row-level locks), a Turn
orchestrator driving the Reply state machine and recovering from
session-not-found, an artifact pipeline backed by ActiveStorage,
sandbox seeding, and tool-display value objects for Turbo Stream
broadcasts. Drop into any Rails 7.1+ app that wants production-grade
OpenCode streaming without rolling boilerplate.

What this version ships:
  - Opencode::Session (AR-coupled lifecycle, row-level locks)
  - Opencode::Turn (Reply state machine, session-not-found recovery)
  - Opencode::Exchange (one turn = one request/response unit)
  - Opencode::Impostor (deterministic mock for tests)
  - Opencode::Sandbox / SandboxFile (per-session FS scratch space)
  - Opencode::Transform (host-rendered artifact pipeline)
  - Opencode::Artifact / MessageArtifacts (ActiveStorage-backed)
  - Opencode::UploadedFilesPrompt (system-prompt builder)
  - Opencode::ToolDisplay (Turbo Stream value objects)
  - Opencode::ErrorReporter (pluggable adapter — Honeybadger/Sentry/etc.)
  - examples/rails_integration.rb — canonical wiring blueprint

53 smoke tests. CI on Ruby 3.2/3.3/3.4.

Ruby >= 3.2. Runtime deps: opencode-ruby = 0.0.1.alpha2,
activerecord/activestorage/activesupport >= 7.1, < 9.0.

See CHANGELOG.md for the alpha1 -> alpha2 delta.

test/opencode/sandbox_test.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require "fileutils"
+require "tmpdir"
+require "marcel"  # SandboxFile (yielded by Sandbox#files) needs marcel
+
+# Smoke test for Opencode::Sandbox: instantiate against a real tmpdir,
+# verify #path, #exists?, and that #files / #file return empty / nil
+# when no sandbox files are present. Behavioral coverage of actual file
+# enumeration lives in the host application where real per-product
+# sandbox configurations exercise the path.
+class Opencode::SandboxTest < Minitest::Test
+  def setup
+    @tmpdir = Dir.mktmpdir("opencode-rails-sandbox-test-")
+  end
+
+  def teardown
+    FileUtils.remove_entry(@tmpdir) if @tmpdir && File.exist?(@tmpdir)
+  end
+
+  def test_path_and_exists_when_directory_present
+    sandbox = Opencode::Sandbox.new(path: @tmpdir)
+    assert_equal @tmpdir, sandbox.path
+    assert sandbox.exists?
+  end
+
+  def test_exists_false_when_path_missing
+    sandbox = Opencode::Sandbox.new(path: File.join(@tmpdir, "missing"))
+    refute sandbox.exists?
+  end
+
+  def test_files_returns_enumerator_yielding_nothing_when_empty
+    sandbox = Opencode::Sandbox.new(path: @tmpdir)
+    # No block given => Enumerator.
+    assert_kind_of Enumerator, sandbox.files
+    assert_equal [], sandbox.files.to_a
+  end
+
+  def test_files_yields_sandbox_files_for_real_entries
+    File.write(File.join(@tmpdir, "notes.md"), "x")
+    File.write(File.join(@tmpdir, "map.md"),   "y")
+
+    sandbox = Opencode::Sandbox.new(path: @tmpdir)
+    basenames = sandbox.files.map(&:basename).sort
+    assert_equal %w[map.md notes.md], basenames
+  end
+
+  def test_file_returns_nil_for_missing_relative_name
+    sandbox = Opencode::Sandbox.new(path: @tmpdir)
+    assert_nil sandbox.file("nope.txt")
+  end
+end