kernel(date): ISO-8601 rendering, validating parse, sexp converters

Adds sexplib and ppx_sexp_conv to the project and wires the ppx into the
kernel library. Date's sexp form is an ISO-8601 atom rather than the opaque
rata die, so data files stay human-editable and parsing revalidates the
1583..9999 domain.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/dune b/test/dune
index 8ee8b87..3d8fa59 100644
--- a/test/dune
+++ b/test/dune
@@ -1,6 +1,6 @@
 (test
  (name test_colitur)
- (libraries colitur_kernel alcotest qcheck qcheck-alcotest))
+ (libraries colitur_kernel alcotest qcheck qcheck-alcotest sexplib))
 
 (cram
  (deps %{bin:colitur}))