feat: make ares self-contained workspace with bundled domain/mt5-client crates

Vendor domain and mt5-client from hermes into crates/ so the repo can
be pushed to GitHub without external path dependencies.

Also includes all bug fixes from autonomous session:
- impulse SL fix (SL at impulse candle low/high, not zone edge)
- pip_size fix for 5-decimal pairs
- fill_ok premature cancellation fix
- TIMEOUT_CANDLES, MIN_FVG_PIPS, MIN_SL_PIPS env vars

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

crates/mt5-client/src/lib.rs

@@ -0,0 +1,7 @@
+mod client;
+mod error;
+mod types;
+
+pub use client::Mt5Client;
+pub use error::Mt5Error;
+pub use types::{HealthStatus, OrderCheckResult, TradeRequest, TradeResult};