Basic shell working.

InputHandler.h

@@ -0,0 +1,28 @@
+/*
+ * InputHandler.h - input abstraction and mapping to commands
+ */
+#ifndef KTE_INPUT_HANDLER_H
+#define KTE_INPUT_HANDLER_H
+
+#include <string>
+
+#include "Command.h"
+
+// Result of translating raw input into an editor command.
+struct MappedInput {
+    bool hasCommand = false;
+    CommandId id = CommandId::Refresh;
+    std::string arg; // optional argument (e.g., text for InsertText)
+    int count = 0;   // optional repeat (C-u not yet implemented)
+};
+
+class InputHandler {
+public:
+    virtual ~InputHandler() = default;
+
+    // Poll for input and translate it to a command. Non-blocking.
+    // Returns true if a command is available in 'out'. Returns false if no input.
+    virtual bool Poll(MappedInput &out) = 0;
+};
+
+#endif // KTE_INPUT_HANDLER_H