docs: add copilot-instructions.md and file-level comments

- Create .github/copilot-instructions.md with project coding standards,
  architecture overview, threading model, and key rules for AI sessions
- Add module description comments to app.cpp, rpc_client.cpp, rpc_worker.cpp,
  embedded_daemon.cpp, xmrig_manager.cpp, console_tab.cpp, settings.cpp
- Add ASCII connection state diagram to app_network.cpp
- Remove /.github/ from .gitignore so instructions file is tracked

src/app.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// app.cpp — Main application: init, shutdown, ImGui render loop, NavPage
+// dispatch, dialog rendering, and frame-level state management.
 
 #include "app.h"
 #include "config/version.h"

src/app_network.cpp

@@ -2,8 +2,32 @@
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
 //
-// app_network.cpp — RPC connection, data refresh, and network operations
+// app_network.cpp — RPC connection, data refresh, and network operations.
 // Split from app.cpp for maintainability.
+//
+// Connection state machine:
+//
+//   [Disconnected]
+//        │
+//        ▼  tryConnect() every 5s
+//   Auto-detect DRAGONX.conf (host, port, rpcuser, rpcpassword)
+//        │
+//        ├─ no config found ──► start embedded daemon ──► retry
+//        │
+//        ▼  post async rpc_->connect() to worker_
+//   [Connecting]
+//        │
+//        ├─ success ──► onConnected()  ──► [Connected]
+//        │                                     │
+//        │                                     ▼  refreshData() every 5s
+//        │                                  [Running]
+//        │                                     │
+//        │                                     ├─ RPC error ──► onDisconnected()
+//        │                                     │                     │
+//        ├─ auth 401 ──► .cookie auth ──► retry│                     ▼
+//        │                                     │              [Disconnected]
+//        └─ failure ──► onDisconnected(reason) ┘
+//                       may restart daemon
 
 #include "app.h"
 #include "rpc/rpc_client.h"

src/config/settings.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// settings.cpp — JSON settings persistence. Loads/saves user preferences
+// to ~/.config/ObsidianDragon/settings.json (Linux/macOS) or %APPDATA% (Windows).
 
 #include "settings.h"
 #include "version.h"

src/daemon/embedded_daemon.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// embedded_daemon.cpp — Manages the dragonxd child process lifecycle:
+// binary discovery, process spawn, stdout/stderr monitoring, crash recovery.
 
 #include "embedded_daemon.h"
 #include "../config/version.h"

src/daemon/xmrig_manager.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// xmrig_manager.cpp — Pool mining process management via xmrig-hac.
+// Spawns xmrig, monitors via HTTP API, tracks hashrate and shares.
 
 #include "xmrig_manager.h"
 #include "../resources/embedded_resources.h"

src/rpc/rpc_client.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// rpc_client.cpp — JSON-RPC client over HTTPS using libcurl.
+// All calls are blocking; run on RPCWorker threads, never on main thread.
 
 #include "rpc_client.h"
 #include "../config/version.h"

src/rpc/rpc_worker.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// rpc_worker.cpp — Background work queue. Executes WorkFn on its own thread,
+// returns MainCb callbacks drained each frame on the main thread.
 
 #include "rpc_worker.h"
 #include <cstdio>

src/ui/windows/console_tab.cpp

@@ -1,6 +1,9 @@
 // DragonX Wallet - ImGui Edition
 // Copyright 2024-2026 The Hush Developers
 // Released under the GPLv3
+//
+// console_tab.cpp — Interactive RPC console with command history,
+// tab completion, daemon log display, and color-coded output.
 
 #include "console_tab.h"
 #include "../material/colors.h"