Port schedule service from Python to Rust + Rouille

- Background scheduler thread (30s interval)
- Cron expression parsing with cron crate
- File-based JSON storage (compatible with existing data)
- HTTP API: CRUD, manual run, history
- ~3MB binary vs ~50MB Python

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "schedule"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rouille = "3.6"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+chrono = { version = "0.4", features = ["serde"] }
+cron = "0.12"
+ureq = { version = "2.9", features = ["json"] }
+uuid = { version = "1.0", features = ["v4"] }
+
+[profile.release]
+strip = true
+lto = true