docs: correct the A5 claim about the form-machine generator

PLAN.md stated that plop-templates/form-machine.hbs generates
runIfSubmitting, and that .claude/skills/form-machine/SKILL.md teaches
it, so the next scaffolded form would recreate the bug RD-06 fixed.

Both are false. The plop template is machine-only: 74 lines, no
@Component, no runIfSubmitting. The skill never mentions it.

Two real sites remain, both teaching the deleted idiom in a code block:
ARCHITECTURE.md:314 and :574, and fp-tea-atomic-design.md:342. RD-09 is
therefore a two-document fix, still worth doing, but not the urgent
generator fix this plan claimed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/project/readable-codebase/PLAN.md

@@ -460,11 +460,20 @@ Submit first — it settles the final shape of the 5 components, and 1b#4 touche
 | B6    | _(optional)_ `NO_SUBORGS`/`NO_TABLES` → `Empty`                                    | Needs a new `$localize` id per app that renders it                                                    |
 | B5    | _(optional, last, alone)_ upload `type:` → `tag:`                                  | ~20 files; see the sed hazard in Risks                                                                |
 
-**A5 is not optional.** `docs/reference/architecture/ARCHITECTURE.md:308-322` and `:574`, and
-`docs/reference/fp-tea-atomic-design.md:338-350`, both teach `runIfSubmitting` verbatim — and
-`plop-templates/form-machine.hbs` **generates it**, as does
-`.claude/skills/form-machine/SKILL.md:65-78`. If the generator is not updated, the next form
-scaffolded in this repo recreates the bug. Update all five in the same commit as A4.
+**A5 — corrected while executing RD-09.** The original claim here was that
+`plop-templates/form-machine.hbs` **generates** `runIfSubmitting`, and that
+`.claude/skills/form-machine/SKILL.md:65-78` teaches it, so that the next scaffolded form
+would recreate the bug. **Both are false**, verified by grep:
+
+- `plop-templates/form-machine.hbs` is **machine-only** — 74 lines, no `@Component`, no
+  `runIfSubmitting`. No generator recreates the bug.
+- `.claude/skills/form-machine/SKILL.md` never mentions it.
+
+Two real sites remain, and both teach the deleted idiom verbatim in a code block:
+`docs/reference/architecture/ARCHITECTURE.md:314` and `:574`, and
+`docs/reference/fp-tea-atomic-design.md:342`. So A5/RD-09 is a two-document fix, still worth
+doing — a teaching document that teaches a deleted idiom is precisely the rot this arc targets
+— but it is not the urgent generator fix this plan originally claimed.
 
 **Scope discipline:** A1 + A2 alone deliver "dispatching cannot silently skip the effect" and
 fix both bugs. If the budget shrinks, stop after A5; B3 and B2 are hygiene, not correctness.