test(opencode): the 2.x schema and CLI, a fake opencode, and an opt-in real-binary contract (Issue #60)

tests/_fake_opencode.py implements the two commands MAM calls (debug paths,
session delete) as measured on 2.0.32; unit tests never run a real opencode
(it would migrate the test database). test_real_opencode_2x_contract runs a
real 2.x opencode, when installed, in a home and tmp dir of its own with
--standalone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

tests/conftest.py

@@ -131,6 +131,7 @@ if _TESTS_DIR not in sys.path:
     sys.path.insert(0, _TESTS_DIR)
 import _mam_state_guard  # noqa: E402
 import _agent_home_guard  # noqa: E402
+import _fake_opencode  # noqa: E402
 
 _BINDING_VARS = ("WORKSPACE_ROOT", "AGENT_SESSIONS_YAML", "MAM_JOBS_DIR", "DELEGATE_JOB_LOGS_DIR")
 _RECORDED_BINDING = {}
@@ -971,9 +972,9 @@ elif cmd1 == "agent":
             os.makedirs(opencode_dir, exist_ok=True)
             odb = os.path.join(opencode_dir, "opencode.db")
             conn = sqlite3.connect(odb)
-            conn.execute("CREATE TABLE IF NOT EXISTS session (id TEXT PRIMARY KEY, directory TEXT, time_created INTEGER, cwd TEXT, created_at REAL)")
+            conn.execute("CREATE TABLE IF NOT EXISTS session_v2 (id TEXT PRIMARY KEY, parent_id TEXT, directory TEXT, time_created INTEGER)")
             now_ms = int(time.time() * 1000)
-            conn.execute("INSERT OR REPLACE INTO session (id, directory, time_created, cwd, created_at) VALUES (?, ?, ?, ?, ?)", (session_uuid, ws_abs, now_ms, ws_abs, time.time()))
+            conn.execute("INSERT OR REPLACE INTO session_v2 (id, directory, time_created) VALUES (?, ?, ?)", (session_uuid, ws_abs, now_ms))
             conn.commit()
             conn.close()
         elif agent_type == "codex":
@@ -1466,25 +1467,8 @@ sys.exit(0)
 """)
     grok_bin.chmod(0o755)
 
-    # 5. opencode mock
-    opencode_bin = bin_dir / "opencode"
-    opencode_bin.write_text("""#!/usr/bin/env python3
-import sys, os
-args = sys.argv[1:]
-if len(args) >= 2 and args[0] == "db" and args[1] == "path":
-    home = os.environ.get("HOME", "")
-    db_path = f"{home}/.local/share/opencode/opencode.db"
-    os.makedirs(os.path.dirname(db_path), exist_ok=True)
-    if not os.path.exists(db_path):
-        import sqlite3
-        conn = sqlite3.connect(db_path)
-        conn.execute("CREATE TABLE IF NOT EXISTS session (id TEXT PRIMARY KEY, directory TEXT, time_created INTEGER)")
-        conn.close()
-    print(db_path)
-    sys.exit(0)
-sys.exit(0)
-""")
-    opencode_bin.chmod(0o755)
+    # 5. opencode mock (the 2.x commands MAM calls, Issue #60)
+    _fake_opencode.write(bin_dir / "opencode")
 
     # 6. codex mock
     codex_bin = bin_dir / "codex"