feat(cli): --lang and --raw, colitur lang, colitur config

Names are Latin by default now; --raw restores the old byte-exact output,
verified against a pre-branch binary built from a clean HEAD checkout, not
merely asserted. day and readings gain a trailing display-name field
(day's own name suffix, readings' own " | name" suffix) rather than a
substitution in the slug's existing position: a name contains spaces and
would otherwise break the space-separated columns, the same reasoning that
already keeps readings a separate command. The field is present only when
it differs from the slug already shown, which is a direct consequence of
Lang.raw being the identity table (no lookup ever misses), not a special
case threaded through day_line/readings_line -- under --raw, or any
language with no entry for a given day, the trailing field is simply
absent, byte for byte what this project printed before naming existed.

An unknown language is an error naming what is available, never a silent
fallback to Latin: a booklet quietly printed in the wrong language is worse
than one that refuses to print. A declared fallback still chains, so a
partial translation shows its fallback language rather than slugs.
lang_dir mirrors data_dir's probe order exactly -- installed prefix, then
build tree -- because an installed binary that finds calendar data but no
language files is the failure this would otherwise ship.

Config (lang/overlay/template/format) is loaded once, unconditionally,
before dispatch: a config file that exists but fails to parse is fatal on
every command, not only the ones that consult it, because a config the
user wrote and colitur cannot honour is not something to silently carry on
past. An unknown key or unknown section is reported and ignored, worded
differently so a misspelled section reads differently from a misspelled
key inside a recognised one. overlay's config default applies only when
zero --overlay flags were given, never merged with a partial CLI list, so
precedence stays flag > config > default in one direction throughout.

colitur lang --list/--dump/--check and colitur config --show are what make
"anyone can write a language file" true rather than merely permitted, the
same pattern the overlay system already established with new-overlay and
check. --check reports what is missing AND rejects an unknown slug (exit
1), because a key matching nothing is silently dead and its author would
otherwise never learn why their own name does not appear. --dump emits
sections in a fixed order (Lang.keys' own global sort keeps every
section's keys contiguous), so two dumps of the same table are
byte-identical. config --show resolves through the same Config.resolve
every other command uses -- deliberately no separate provenance function,
so the two cannot disagree -- and previews exactly what flags given on the
same command line would resolve to anywhere else.

One authorized change outside this task's own file list: emit_ics.ml's
SUMMARY line was reading the unlocalised rank/colour pair ("class-1,
white") beside an already-localised name, where the JSON schema right next
to it correctly carries rank_name/colour_name ("II classis"/"albus").
Found while reviewing the published site; fixed at the source.

1 files changed, 11 insertions, 2 deletions

diff --git a/lib/render/emit_ics.ml b/lib/render/emit_ics.ml
index 4e06eae..b212930 100644
--- a/lib/render/emit_ics.ml
+++ b/lib/render/emit_ics.ml
@@ -57,9 +57,18 @@ let event b ~rite ~dtstamp d =
   if iso <> "" then begin
     (* [name] is the view's own resolved display string (view.ml) -- no
        further fallback needed here: under [Lang.raw] it already equals
-       [slug], which is what a miss used to require picking by hand. *)
+       [slug], which is what a miss used to require picking by hand.
+
+       [rank_name]/[colour_name], not the bare [rank]/[colour]: those two
+       carry the kernel's own unlocalised strings ("class-1", "white"),
+       exactly the raw-slug shape [name] itself moved away from -- SUMMARY
+       is a human-facing calendar entry, and printing "(class-1, white)"
+       beside a properly resolved name (e.g. "II classis, albus") was the
+       one field this emitter had not yet been updated to localise; the
+       JSON/CSV/XML emitters already expose both pairs and a template author
+       already has to choose the localised one deliberately. *)
     let name = s d "name" in
-    let summary = Printf.sprintf "%s (%s, %s)" name (s d "rank") (s d "colour") in
+    let summary = Printf.sprintf "%s (%s, %s)" name (s d "rank_name") (s d "colour_name") in
     let desc =
       String.concat "\n"
         (List.filter (fun x -> x <> "")