plan: intake to plan by a model; doors, labelled groups, the whole card

Work from another session, committed as found (tests green):

- `plan` reads an intake into a plan.yaml (a model decides needs,
  stages, forms and budgets; a person reads the result before build).
- Plans gain `doors` (a first question before the forms, when a front
  door would carry more than five needs), `groups` with labels that a
  select may draw its options from (`options_from: groups`), `private`
  fields kept off public pages, `multiple` selects, and `max_fields`
  as what the intake said the person will tolerate.
- `card.rs`: an alternative as the visitor meets it, in text, so the
  answering visitor and `rate` read the served card, not the heading.
- `rate` reads followup pages from the repo and reports "what happens
  next" as not measured rather than zero when it cannot.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4jrCgLiKKHAEFuZUJjckH

src/simulate.rs

@@ -410,7 +410,7 @@ pub(crate) fn all_routes(bucket: &Value, done: &[&str]) -> Vec<Vec<Move>> {
 /// Models often answer "Heading: its description" or change the case.
 /// The pick is the longest option heading the answer starts with;
 /// anything else is kept verbatim and counts as a misroute.
-fn resolve_choice(names: &[&str], raw: &str) -> String {
+pub(crate) fn resolve_choice(names: &[&str], raw: &str) -> String {
     let answer = raw.trim().trim_matches('"').to_lowercase();
     names
         .iter()