libghostty als zweite Terminal-Engine integriert (Default ghostty, SwiftTerm Fallback)

- vendor/libghostty: vorgebaute macOS-libghostty.a (arm64) + Header + Build-Patches + README
- Sources/CGhostty: C-Modul der libghostty-C-API
- Sources/MiniTerm/Ghostty.swift: GhosttyApp + GhosttySurfaceView (Surface, Input, Größe, Fokus)
- main.swift: Engine-Wahl per Info.plist MTEngine
- Package.swift: CGhostty-Target + Link gegen libghostty + Frameworks
- STATUS.md: Stand, Build-Weg (macOS-15-VM), offene Punkte

vendor/libghostty/include/ghostty/vt/paste.h

@@ -0,0 +1,75 @@
+/**
+ * @file paste.h
+ *
+ * Paste utilities - validate and encode paste data for terminal input.
+ */
+
+#ifndef GHOSTTY_VT_PASTE_H
+#define GHOSTTY_VT_PASTE_H
+
+/** @defgroup paste Paste Utilities
+ *
+ * Utilities for validating paste data safety.
+ *
+ * ## Basic Usage
+ *
+ * Use ghostty_paste_is_safe() to check if paste data contains potentially
+ * dangerous sequences before sending it to the terminal.
+ *
+ * ## Example
+ *
+ * @code{.c}
+ * #include <stdio.h>
+ * #include <string.h>
+ * #include <ghostty/vt.h>
+ * 
+ * int main() {
+ *   const char* safe_data = "hello world";
+ *   const char* unsafe_data = "rm -rf /\n";
+ * 
+ *   if (ghostty_paste_is_safe(safe_data, strlen(safe_data))) {
+ *     printf("Safe to paste\n");
+ *   }
+ * 
+ *   if (!ghostty_paste_is_safe(unsafe_data, strlen(unsafe_data))) {
+ *     printf("Unsafe! Contains newline\n");
+ *   }
+ * 
+ *   return 0;
+ * }
+ * @endcode
+ *
+ * @{
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Check if paste data is safe to paste into the terminal.
+ *
+ * Data is considered unsafe if it contains:
+ * - Newlines (`\n`) which can inject commands
+ * - The bracketed paste end sequence (`\x1b[201~`) which can be used
+ *   to exit bracketed paste mode and inject commands
+ *
+ * This check is conservative and considers data unsafe regardless of
+ * current terminal state.
+ *
+ * @param data The paste data to check (must not be NULL)
+ * @param len The length of the data in bytes
+ * @return true if the data is safe to paste, false otherwise
+ */
+bool ghostty_paste_is_safe(const char* data, size_t len);
+
+#ifdef __cplusplus
+}
+#endif
+
+/** @} */
+
+#endif /* GHOSTTY_VT_PASTE_H */