Add a dump-scan demonstrator (vmie_scan)

A thin CLI proving the OS-agnostic dump path end to end: open one or more raw
memory dumps as flat identity images (vmie_mem) and scan them all for an
IDA-style pattern, printing each hit as source:gpa. Two-pass (count, then size
the buffer exactly) so nothing is silently truncated.

Kept separate from vmie_cli rather than folded in as a subcommand: vmie_cli
demonstrates live win32 bring-up, this demonstrates the source-agnostic scan.
Its source includes only the public memmodel/sigscan/scan headers and names no
Windows symbol - it compiles against include/ alone.

CMakeLists.txt

@@ -35,6 +35,11 @@ add_executable(vmie_cli src/cli.c)
 target_link_libraries(vmie_cli PRIVATE vmie)   # public include/ comes via vmie (PUBLIC)
 target_compile_options(vmie_cli PRIVATE -Wall -Wextra)
 
+# ---- host: dump-scan demonstrator (OS-agnostic, no win32) ----------------
+add_executable(vmie_scan src/scan_cli.c)
+target_link_libraries(vmie_scan PRIVATE vmie)
+target_compile_options(vmie_scan PRIVATE -Wall -Wextra)
+
 # ---- guest: cross-compile to Windows x86-64 via mingw-w64 ---------------
 find_program(MINGW_CC NAMES x86_64-w64-mingw32-gcc REQUIRED)
 set(VMIE_STARTUP ${CMAKE_CURRENT_BINARY_DIR}/vmie-startup.exe)