fix(build): strip \r\n from all .py files — CRLF breaks patch_ops.sh text matching

31 files had Windows line endings (\r\n) from merge commit. This causes
patch_ops.sh replace_once() to fail: anchor strings use \n but file
content has \r\n, so no match → patch fails → docker build fails.

Also added .gitattributes to force LF for all text files going forward.

.gitattributes

@@ -0,0 +1,10 @@
+# Force LF line endings for all text files
+* text=auto eol=lf
+*.py text eol=lf
+*.sh text eol=lf
+*.cu text eol=lf
+*.cuh text eol=lf
+*.yaml text eol=lf
+*.yml text eol=lf
+*.md text eol=lf
+Dockerfile text eol=lf