feat(render): per-flavour escaping and RFC 5545 line folding

Six flavours: latex, groff, html, xml, ics, none. Markdown, AsciiDoc and
plain text map to none deliberately -- their metacharacters are
context-dependent and escaping them aggressively produces worse output
than not escaping.

An unrecognised extension returns None rather than falling back to none:
guessing the flavour wrong produces malformed output that looks fine
until it does not.

Folding backs off to a non-continuation byte, so a fold never splits a
UTF-8 sequence -- the failure mode that would corrupt Polish and Latin
names in a published feed.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/dune b/test/dune
index e20450b..1ef1b57 100644
--- a/test/dune
+++ b/test/dune
@@ -1,6 +1,6 @@
 (test
  (name test_colitur)
- (libraries colitur_kernel rite_ef alcotest qcheck qcheck-alcotest sexplib)
+ (libraries colitur_kernel colitur_render rite_ef alcotest qcheck qcheck-alcotest sexplib)
  (deps
   ../data/ef/sanctoral.sexp
   ../data/ef/adjustments.sexp