Remove stray grep.exe.stackdump; ignore *.stackdump

.gitignore

@@ -3,3 +3,6 @@ data/
 .env
 .claude/
 *.code-workspace
+
+# stray Windows crash dumps
+*.stackdump

grep.exe.stackdump

@@ -1,31 +0,0 @@
-Stack trace:
-Frame         Function      Args
-0007FFFFBBB0  0002100603A4 (0000000000B0, 0007FFFFDC10, 0007FFFFC730, 0007FFFFDC10) msys-2.0.dll+0x203A4
-0007FFFFC490  0002100625FE (0007FFFFC730, 000000000000, 000000000180, 000000000000) msys-2.0.dll+0x225FE
-0007FFFFC490  0002100C1794 (0007FFFFC6F0, 000000000000, 000000000000, 0007FFFFC700) msys-2.0.dll+0x81794
-000000000006  0002100BD229 (7FFA00000346, 0007FFFFC700, 000000000000, 7FFA46EDAB50) msys-2.0.dll+0x7D229
-0007FFFFC848  0002100BD62A (0007FFFFC858, 000A00000000, 0000000000B5, 0000000000B5) msys-2.0.dll+0x7D62A
-0007FFFFC848  000210213B18 (000000000000, 000A00000030, 000000000000, 000000000000) msys-2.0.dll+0x1D3B18
-0007FFFFC848  00010042A1E5 (0002100A7AB3, 000000000000, 000A00000520, 0000000001F0) grep.exe+0x2A1E5
-0007FFFFCB80  000100404B7C (000000000014, 0007FFFFCB80, 000000000000, 000000000000) grep.exe+0x4B7C
-0007FFFFCB80  000100429678 (0002100455E0, 000000714950, 000000000148, 000000000000) grep.exe+0x29678
-0007FFFFCD30  000210047F11 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x7F11
-000000000000  000210045AC3 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x5AC3
-0007FFFFFFF0  000210045B74 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x5B74
-End of stack trace
-Loaded modules:
-000100400000 grep.exe
-7FFA46D60000 ntdll.dll
-7FFA045B0000 aswhook.dll
-7FFA46060000 KERNEL32.DLL
-7FFA44190000 KERNELBASE.dll
-000430B30000 msys-intl-8.dll
-0005603F0000 msys-iconv-2.dll
-000210040000 msys-2.0.dll
-0004C36D0000 msys-pcre-1.dll
-7FFA46C10000 advapi32.dll
-7FFA46B50000 msvcrt.dll
-7FFA44B50000 sechost.dll
-7FFA46180000 RPCRT4.dll
-7FFA43520000 CRYPTBASE.DLL
-7FFA449D0000 bcryptPrimitives.dll