fix(install): ship the OF runtime data files, guard the installed layout

data/dune's install stanza named only the four EF runtime files, so a
`dune install`ed colitur exited 2 on any --rite of invocation
(`failed to load .../data/of/calendar-2002.sexp`) -- the branch's
headline feature was dead on an installed binary. Add all 15 OF
files (calendar-2002.sexp, the 13 amendments/*.sexp, lectionary.sexp)
to the (files ...) stanza, following the existing ef/ entries' form
and the stanza's own stated rule (deliberately not the litcal
allow-list, a test fixture, same reasoning already given for the EF
pair).

Add a regression guard for the class of bug, not just this instance:
`make check-install` performs a real `dune install --prefix <scratch>`
and runs both rites against the INSTALLED binary, asserting exit 0
and the expected day count. test/cli.t's cram sandbox binds
%{bin:colitur} inside the build tree, where data_dir()/of_data_dir()'s
build-tree fallback candidate resolves even when the installed one is
missing entirely -- so no cram test could have caught this. Wired
into `make check` (unlike check-schema/check-templates/check-citations,
which skip when an optional external tool is absent) since installing
needs nothing beyond what building already needs. Verified the guard
has teeth: reverted data/dune to the pre-fix version and confirmed
check-install fails loudly naming the missing file.

1 files changed, 27 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index d82d320..13df353 100644
--- a/Makefile
+++ b/Makefile
@@ -34,6 +34,33 @@ test: ## fast suite (~5s): properties sample 200 years
 
 check: ## full gate (~2min): every year 1583-9999, not a sample
 	COLITUR_EXHAUSTIVE_SWEEP=1 $(DUNE) dune test --force
+	$(MAKE) check-install
+
+# C1 fix-wave regression guard (final-review.md, 2026-08-25-colitur-of-phases-3-5):
+# a `dune install`ed colitur exited 2 on `--rite of` because data/dune never
+# named the OF runtime files -- and nothing in the suite caught it, because
+# test/cli.t's cram sandbox binds %{bin:colitur} inside the BUILD TREE, where
+# [data_dir]/[of_data_dir]'s build-tree fallback candidate resolves even when
+# the installed one is missing entirely. This target is the guard: it installs
+# to a scratch prefix -- the exact `dune install --prefix X` the review used to
+# reproduce C1, not a hand-rolled copy -- and runs BOTH rites against the
+# installed binary only, asserting exit 0 and the expected day count. Wired
+# into `check` (not opt-in like check-schema/check-templates/check-citations
+# above, which skip when an external tool is missing) because installing needs
+# nothing beyond what building already needs.
+check-install: build ## regression guard: run an INSTALLED colitur (both rites), not just the build tree
+	@set -e; \
+	scratch=$$(mktemp -d); \
+	trap 'rm -rf "$$scratch"' EXIT; \
+	$(DUNE) dune install --prefix "$$scratch" >/dev/null; \
+	test -f "$$scratch/share/colitur/of/calendar-2002.sexp" || \
+	  { echo "check-install: share/colitur/of/calendar-2002.sexp was not installed" >&2; exit 1; }; \
+	ef_lines=$$("$$scratch/bin/colitur" day 2026 | wc -l); \
+	of_lines=$$("$$scratch/bin/colitur" day --rite of 2026 | wc -l); \
+	test "$$ef_lines" -eq 365 || { echo "check-install: installed 'day 2026' (EF) printed $$ef_lines lines, want 365" >&2; exit 1; }; \
+	test "$$of_lines" -eq 365 || { echo "check-install: installed 'day --rite of 2026' printed $$of_lines lines, want 365" >&2; exit 1; }; \
+	"$$scratch/bin/colitur" readings --rite of 2026 >/dev/null; \
+	echo "check-install: installed EF ($$ef_lines lines) and OF ($$of_lines lines) both run cleanly from a scratch prefix"
 
 check-schema: build ## validate emitted XML against schema/colitur-v1.xsd (needs xmllint; skipped if absent)
 	@if command -v xmllint >/dev/null 2>&1; then \