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/src/lib.rs

@@ -0,0 +1,13 @@
+mod wire;
+mod frame;
+
+pub use wire::{
+    WireValue, WireWidgetState, WireWidgetError, WireDisplayHint,
+    WireLayoutNode, WireContainerNode, WireLayoutChild, WireDirection, WireSizing,
+    WireKeyValue,
+};
+pub use frame::{
+    ServerMessage, ClientMessage, WidgetDescriptor,
+    encode, decode_server_message, encode_client, decode_client_message,
+    MAX_FRAME_SIZE,
+};