add all crates: domain, protocol, application, client, adapters, ESP32 firmware

Server: domain (entities, value objects, ports), protocol (postcard wire types),
application (config service, data projection), adapters (config-memory, tcp-server),
bootstrap (composition root with fake data).

Client: client-domain (layout engine, render tree, HAL ports),
client-application (message handling, repaint commands),
adapters (tcp-client, display-terminal), client-desktop (end-to-end working).

ESP32: client-esp32 firmware with ILI9341 display over SPI, WiFi networking.
Display test verified on hardware — landscape orientation, text rendering works.

60 workspace tests, all passing.

crates/protocol/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "protocol"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+domain.workspace = true
+serde.workspace = true
+postcard.workspace = true
+
+[dev-dependencies]