Replace gRPC Backend (#10)

**Rationale:**

Having two separate servers and communication methods resulted in additional maintenance & the need to convert often between backend & frontend data types.
By moving the backend communication off of gRPC and to just use websockets it both gives more control & allows for simplification of the implementation.

#8

**Changes:**

- Replaces gRPC backend.
  - New implementation automatically handles reconnect logic
- Implements an api layer
- Migrates examples to the api layer
- Implements a proc macro to make command handling easier
- Implements unit tests for the api layer (90+% coverage)
- Implements integration tests for the proc macro (90+% coverage)

Reviewed-on: #10
Co-authored-by: Sergey Savelyev <sergeysav.nn@gmail.com>
Co-committed-by: Sergey Savelyev <sergeysav.nn@gmail.com>

server/Cargo.toml

@@ -6,25 +6,20 @@ version = "0.1.0"
 authors = ["Sergey <me@sergeysav.com>"]
 
 [dependencies]
-fern = "0.7.1"
-log = "0.4.29"
-prost = "0.13.5"
-rand = "0.9.0"
-tonic = { version = "0.12.3" }
-tokio = { version = "1.43.0", features = ["rt-multi-thread", "signal", "fs"] }
-chrono = "0.4.42"
-actix-web = { version = "4.12.1", features = [ ] }
-actix-ws = "0.3.0"
-tokio-util = "0.7.17"
-serde = { version = "1.0.228", features = ["derive"] }
-serde_json = "1.0.145"
-hex = "0.4.3"
-papaya = "0.2.3"
-thiserror = "2.0.17"
-derive_more = { version = "2.1.0", features = ["from"] }
-anyhow = "1.0.100"
-sqlx = { version = "0.8.6", features = [ "runtime-tokio", "tls-native-tls", "sqlite" ] }
-uuid = { version = "1.19.0", features = ["v4"] }
-
-[build-dependencies]
-tonic-build = "0.12.3"
+actix-web = { workspace = true, features = [ ] }
+actix-ws = { workspace = true }
+anyhow = { workspace = true }
+api = { path = "../api" }
+chrono = { workspace = true }
+derive_more = { workspace = true, features = ["from"] }
+fern = { workspace = true, features = ["colored"] }
+futures-util = { workspace = true }
+log = { workspace = true }
+papaya = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+sqlx = { workspace = true, features = [ "runtime-tokio", "tls-rustls-ring-native-roots", "sqlite" ] }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["rt-multi-thread", "signal", "fs"] }
+tokio-util = { workspace = true }
+uuid = { workspace = true }