(** Shapes a civil year of resolved days into the value a template renders
    against (spec section 4).

    This layer exists because a month grid needs leading blank cells, week
    bucketing and an "is this cell in the current month" test, and a logic-less
    template can compute none of it. Shaping the data here keeps the engine
    logic-less AND makes the grid template trivial. The view model IS the design.

    Both [weeks] and [days] are offered at every level: the booklet walks
    [days], the grid walks [weeks]. One model, two artefacts, no second code
    path that could drift.

    Colours are exposed as six booleans rather than a hex string: hex would bake
    a presentation policy into the engine, and LaTeX, groff and HTML each want a
    different colour expression. Exactly one of the six is true on every day. *)

val of_days :
  lang:Colitur_naming.Lang.t ->
  vocab:('s, 'r) Colitur_kernel.Vocab.t ->
  rite:string ->
  year:int ->
  ('s, 'r) Colitur_kernel.Liturgical_day.t list ->
  Template.value
(** [of_days ~lang ~vocab ~rite ~year days] where [days] is one civil year,
    1 January to 31 December, in order. Pure and total.

    [lang] resolves every display string -- a day's [name], its localised
    [weekday]/[rank_name]/[colour_name]/[season_name], each month's [name],
    and the top-level [term] vocabulary and [weekday_headings]. [name] is a
    PLAIN STRING, not the old lang-keyed object: a dotted [{{name.la}}]
    reference that misses falls back WHOLESALE to the enclosing scope (a
    month's own [name.la]), which is how a printed booklet came to show
    "Ianuarius" in place of a feast with no Latin name. A plain string has no
    dotted path to fall back through, so that hazard is unrepresentable.
    [slug] is untouched by [lang] -- it stays the stable machine key,
    identical between any two calls that differ only in [lang]. Pass
    {!Colitur_naming.Lang.raw} for the pre-naming behaviour, under which
    [name] equals [slug] exactly (this is what CLI [--raw] uses). *)