fix(pampa): pin test fixtures and snapshots to LF via .gitattributes

core.autocrlf=true corrupts pampa's LF-committed qmd fixtures and
.snap baselines to CRLF on Windows checkout, causing spurious
snapshot/roundtrip/corpus test failures unrelated to actual code
behavior. Mirrors the existing quarto-doctemplate/.gitattributes
precedent (PR #329): pin on-disk fixtures to LF for checkout
determinism, independent of the engine's CRLF-preserve policy which
is exercised via in-source tests, never via file-based snapshots.

Author: cderv

crates/pampa/.gitattributes

@@ -0,0 +1,8 @@
+# Pampa test fixtures and snapshot baselines must stay LF on every platform
+# so the snapshot/roundtrip/corpus tests are deterministic regardless of
+# core.autocrlf. The engine's line-ending *preserve* policy is exercised by
+# in-source CRLF tests (see claude-notes/designs/line-ending-preserve.md),
+# never by these on-disk fixtures.
+tests/** text eol=lf
+snapshots/** text eol=lf
+test-fixtures/** text eol=lf