Expand logic state model

docs/host_logic_rebuild.md

@@ -0,0 +1,72 @@
+# Host LGC Rebuild
+
+## Goal
+
+Keep the logic layer small, readable, and teachable.
+
+The logic layer should:
+
+- own connection state
+- own handshake state
+- call DRI for bytes
+- call COM for frame and packet parsing
+- expose a small interface to APP
+
+The logic layer should not:
+
+- parse serial bytes by itself
+- enumerate devices directly
+- own widget code
+
+## Completed Nodes
+
+### Node 1: function executor shell
+
+Files:
+
+- `KeyBorad/KeyBorad/LOGIC/Lgc_FunctionExecutor.h`
+- `KeyBorad/KeyBorad/LOGIC/Lgc_FunctionExecutor.cpp`
+
+Design notes:
+
+- keep function execution out of session code
+- reserve one place for OS-specific actions
+- keep the initial implementation small
+
+### Node 2: state model
+
+Files updated in this step:
+
+- `KeyBorad/KeyBorad/LOGIC/Lgc_State.h`
+
+Design notes:
+
+- state is plain data
+- connection text and last action text live here
+- handshake result fields live here
+
+### Node 3: session handshake path
+
+Files planned next:
+
+- `KeyBorad/KeyBorad/LOGIC/Lgc_Session.h`
+- `KeyBorad/KeyBorad/LOGIC/Lgc_Session.cpp`
+
+Target behavior:
+
+- try CDC handshake
+- store the active transport
+- read next parsed packet
+
+### Node 4: core facade
+
+Files planned after session:
+
+- `KeyBorad/KeyBorad/LOGIC/Lgc_Core.h`
+- `KeyBorad/KeyBorad/LOGIC/Lgc_Core.cpp`
+
+Target behavior:
+
+- give APP one small entry point
+- forward start/poll/close to session
+- refresh state from handshake results