LINUS ROUND 1: Delete dead code (rust/c), generic Store[T], tests, slim main.go

- Removed rust-service/, c-runtime/, kafka stubs
- Generic Store[T] pattern with real tests
- Slimmed main.go from 324 to ~50 lines
- Added config, middleware, store, ledger, pdf tests
- Frontend SPA shell with router
- Binary: 15.5MB -> 12MB

rust-service/Cargo.toml

@@ -1,28 +0,0 @@
-[package]
-name = "boc-rust-service"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
-tokio = { version = "1.35", features = ["full", "rt-multi-thread"] }
-tokio-postgres = { version = "0.7", features = ["with-uuid-1", "with-serde_json-1", "with-chrono-0_4"] }
-serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
-axum = "0.7"
-tower = "0.4"
-tower-http = { version = "0.5", features = ["cors", "trace"] }
-tracing = "0.1"
-tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-chrono = { version = "0.4", features = ["serde"] }
-uuid = { version = "1.6", features = ["serde", "v4"] }
-dashmap = "5.5"
-rayon = "1.8"
-libc = "0.2"
-
-[lib]
-name = "boc_rust"
-crate-type = ["cdylib", "staticlib", "rlib"]
-
-[[bin]]
-name = "boc-rust-service"
-path = "src/main.rs"