AirPlan V2 initial release — unified scheduler with 12 sub-modes

Merges 8 V1 plugins into 1 unified plugin, adds 4 new components (dep, tst, sec, rvr).
12 sub-modes: arc, eng, do, dbg, xdb, sdb, ndb, ctx, dep, tst, sec, rvr.
L1 code-level guarantees: atomic writes, file locks, evidence gating, forced debug routing,
3-phase arc gate, evidence-first debug gate, Chinese language lock, scheduler boundary.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/air_runtime/__init__.py

@@ -0,0 +1,20 @@
+# air_runtime — AirPlan V2 核心运行时库
+
+from air_runtime.io import atomic_json_write, safe_json_load
+from air_runtime.lock import FileLock
+from air_runtime.utils import ordered_unique, session_stamp, normalize_policy, sanitize_task_id, sanitize_marker
+from air_runtime.events import EventLog
+from air_runtime.task_graph import TaskGraph, PlanDelta
+from air_runtime.worktree import WorktreeIsolation, RegionConflictDetector, ConflictLevel
+from air_runtime.evidence_gate import EvidenceGatePolicy, EvidenceClass
+from air_runtime.contracts import now_iso, WorkerResult, TaskRecord, DeploymentRecord
+from air_runtime.paths import (
+    airplan_root, todo_path, plan_path,
+    state_root, engine_state_path, worker_state_path,
+    arc_state_path, dbg_state_path, xdb_state_path,
+    sdb_state_path, ndb_state_path, ctx_state_path,
+    dep_state_path, tst_state_path, sec_state_path, rvr_state_path,
+    required_project_artifacts,
+)
+
+__version__ = "2.0.0"