Don't force init on scoped commands when PRODUCT.md is missing (#277)

* Don't force init on scoped commands when PRODUCT.md is missing

Setup step 1 told the agent: "If it reports NO_PRODUCT_MD, stop and
follow reference/init.md before doing anything else." For a project with
no PRODUCT.md, that turned every scoped request (polish, critique, audit,
layout, ...) into a full from-scratch init detour. The user asks to
polish one button and the skill instead starts writing PRODUCT.md from
the beginning. Faced with that gate, agents also frequently abandon the
command and do an ad-hoc pass without loading the command reference.

Make the gate command-aware. A missing PRODUCT.md still routes into init
for the from-scratch build flows where captured product context is the
point (init, craft, shape). For any other command, a scoped request
against existing code, the code is the context: proceed with the
requested command, infer the register from the surface in focus, and
offer /impeccable init once as a suggestion rather than a blocker.

- skill/SKILL.src.md: rewrite the step 1 NO_PRODUCT_MD rule; reconcile
  the no-argument routing rule so it leads the menu with init instead of
  silently jumping into it; extend the craft init-then-resume footnote to
  cover shape, now also a from-scratch flow.
- skill/scripts/context.mjs: soften the NO_PRODUCT_MD message to defer to
  the step 1 rule instead of "Stop the current task"; refresh the stale
  file-level JSDoc that still described the old empty-stdout signal.
- tests/skill-behavior/scenarios.test.mjs: add scenario 10 (scoped
  command + no PRODUCT.md proceeds without forcing init) and scenario 11
  (shape + no PRODUCT.md still diverts into init). Scenario 1 (craft
  diverts) stays green and pins the build path.

Source-only per repo convention; provider and plugin copies are
regenerated by the maintainer's build:skills sync.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Fix missing-context routing for build intent

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: Paul Bakaus <paul.bakaus@gmail.com>

skill/scripts/context.mjs

@@ -1,8 +1,10 @@
 /**
  * Context loader: prints PRODUCT.md (and DESIGN.md if present) as one
- * markdown block on stdout, or exits with empty stdout when no PRODUCT.md
- * is found anywhere. The skill keys off "empty stdout" to branch into the
- * init flow.
+ * markdown block on stdout, or prints a `NO_PRODUCT_MD:` message when no
+ * PRODUCT.md is found anywhere. The skill keys off that message to branch:
+ * from-scratch build commands (init / teach / craft / shape) and clear
+ * build/shape intent divert into the init flow, while scoped commands proceed
+ * using the existing code as context.
  *
  * Path resolution (first match wins):
  *   1. Active project root, if PRODUCT.md or DESIGN.md is there
@@ -860,8 +862,11 @@ async function cli() {
     // — cheap models miss the empty case more often than the explicit one.
     const parts = [
       'NO_PRODUCT_MD: This project has no PRODUCT.md yet. ' +
-      'Stop the current task, load reference/init.md, and follow its ' +
-      'instructions to write PRODUCT.md before resuming.',
+      'Follow SKILL.md Setup step 1: for `init`, `teach`, `craft`, `shape`, ' +
+      'or wording that clearly maps to a from-scratch build/shape flow, load ' +
+      'reference/init.md and write PRODUCT.md first; for any other (scoped) ' +
+      'command against existing code, proceed using the code as context and ' +
+      'offer `/impeccable init` as a suggestion (do not block).',
     ];
     parts.push(buildResolvedContextDirective(ctx, cliOptions, { targetExists }));
     if (shouldWarnMissingTarget(ctx, targetProvided, targetExists)) {