feat(commands): implement Auto-AGENTS.md orchestration state system (#412)

This implements the orchestration state tracking system for the /init command
as specified in ORCHESTRATE/AGENT_7_INIT.md.

Key features:
- Atomic file writing (atomic.rs): Ensures files are never in corrupted state
  using write-to-temp-then-rename pattern with fsync
- AGENTS.md hierarchy support (hierarchy.rs): Loads from global, project, and
  local scopes (similar to Claude Code)
- Orchestration state tracking (state.rs): YAML-based state files for tracking
  multi-agent progress with auto-save functionality

All file operations now use atomic writes to prevent corruption during
concurrent access or system interruptions.

Co-authored-by: Droid Agent <droid@factory.ai>

Author: echobt

Cargo.lock

@@ -24,6 +24,7 @@ tokio = { workspace = true, features = ["fs", "io-util", "sync"] }
 thiserror = { workspace = true }
 
 # Utilities
+chrono = { workspace = true }
 dirs = { workspace = true }
 tracing = { workspace = true }
 regex-lite = { workspace = true }