docs(skill): feed ssr-form-migration with Phase 10 (Client) learnings

- form-vs-wizard.md: the sub-editor pattern — modeling a parameterized sub-step
  (list ⇄ per-item editor with accept/discard/sort) on the linear engine as
  whole-form swaps driven by routes that mutate session step-data, with a
  pass-through step :decode that re-reads the list via a non-stripped `wiz` hidden.
- scorecard.md: Phase 10 row (defrecord 9→0, multimethods→case, grid+schemas+
  power-query preserved verbatim, blank-address recurrence, 71/71 green).

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

.claude/skills/ssr-form-migration/reference/form-vs-wizard.md

@@ -229,3 +229,36 @@ accounts totals all post the whole `#wizard-form`; in the engine that form carri
 `invoice/*` fields + the opaque `wizard-id`, so a fragment decodes what it needs straight from
 `form-params` (and, for a cross-step value like the invoice total on the accounts step, reads
 `ws/get-all` via the posted `wizard-id`). No `mm/wrap-decode-multi-form-state` stack survives.
+
+## Sub-editor: a parameterized sub-step on the linear engine (Phase 10, bank accounts)
+
+The engine's steps are a flat list — it has no nested/parameterized step like the old
+mm `[:bank-account which]`. When a step owns a *collection you edit one item at a time*
+(a list view ⇄ a per-item editor, with accept/discard/sort), don't try to bend the step
+list. Model it as a **sub-editor of that step**, entirely in whole-form swaps:
+
+- **The step renders the list view** (cards/rows + an "add" affordance). Each item's
+  edit/new control is an `hx-get` that targets `#wizard-form` with `hx-swap outerHTML` and
+  carries `?wizard-id=<id>&index=N` (the wizard-id is in the render ctx).
+- **The editor is its own `<form id="wizard-form">`** (so it swaps cleanly and the next
+  swap replaces it) with the item's fields + hidden `wizard-id` + a hidden item index. Its
+  Accept `hx-post`s an accept route; Discard `hx-get`s a discard route. It is NOT a wizard
+  step and does NOT go through `handle-step-submit`.
+- **Dedicated routes mutate the step's data in the session directly** and re-render the
+  list via the engine: read `(ws/step-data session wid <step-key>)`, splice the decoded
+  item into the vector (`assoc` at index, or `conj` to append for new), `ws/put-step`, then
+  `(wizard2/render-wizard {:config … :wizard-id wid :session session' :request request})`
+  and `(assoc :session session')`. Discard just re-renders from the unchanged session.
+- **The step's own `:decode` is a pass-through.** Because the list lives in the session
+  (managed by the sub-editor, not by in-form inputs), the step's Next must re-affirm it,
+  not decode it from a near-empty form. Read it back with the wizard-id — but the engine
+  strips `wizard-id`/`current-step`/`direction` from form-params before `:decode`, so smuggle
+  it through an extra hidden the engine leaves alone (we used `wiz`):
+  `(or (ws/step-data (:session request) (get-in request [:form-params "wiz"]) <step-key>) {…})`.
+- Give the step a no-op `:validate` (`(fn [_ _] nil)`) — items are validated on Accept.
+- Clean control keys out of the decoded item before storage (`select-keys` to `:db/id` +
+  the entity's own namespace) so `wizard-id`/index/`:new?` never reach datomic.
+
+This keeps the doctrine intact (every byte is a whole-form swap of `#wizard-form`; no EDN
+snapshot rides the page) while giving the linear engine an add/edit/sort sub-flow it has
+no native concept for.

.claude/skills/ssr-form-migration/reference/scorecard.md

@@ -293,3 +293,38 @@ blank-nested-entity upsert error (see `gotchas.md`).
 create across all 5 steps persists; edit opens prefilled and a rename persists; a too-short
 name blocks advancing). Create + edit semantics also confirmed at the REPL (incl. the
 cookie-session EDN round-trip). `maybe-spread-locations`-style domain helpers untouched.
+
+---
+
+## Phase 10 — New/Edit Client (the largest modal: 7 steps + a bank-account sub-editor)
+
+**Coupling outcome:** `defrecord` **9 → 0** (InfoModal / MatchesModal / ContactModal /
+BankAccountsModal / IntegrationsModal / BankAccountModal / CashFlowModal /
+OtherSettingsModal + ClientWizard all gone), `mm/` **0**, `fc/` cursor refs **0**,
+`step-params[…]` **0**, `bank-account-card`/`bank-account-form` multimethods (dispatched on
+`(comp deref :bank-account/type)`) collapsed to plain `case` on a data map. Routes: the
+broken `navigate` + `discard` are deleted; four bank-account sub-editor routes added
+(new/edit/accept/discard) + sort kept. The grid, both form schemas, and ~200 lines of
+sales power-query export are preserved **verbatim** (stitched around the rewritten wizard
+region rather than retyped).
+
+**The new pattern — a parameterized sub-step on a linear engine.** The old
+`[:bank-account which]` mm sub-step (open one account, Accept/discard/sort, back to the
+list) doesn't map onto wizard2's flat step list. Modeled instead as a *sub-editor of the
+bank-accounts step*: see `form-vs-wizard.md` ("Sub-editor"). Key moves: list + editor are
+both whole-form swaps of `#wizard-form`; dedicated routes mutate `:bank-accounts`
+step-data in the session via `ws/put-step` and re-render through `wizard2/render-wizard`;
+the step's own `:decode` is a **pass-through** that re-reads the session list (via a `wiz`
+hidden the engine doesn't strip) so Next never wipes the out-of-band list.
+
+**Fixes carried/!surfaced:** new-vs-edit keyed off `:db/id` presence (engine always POSTs,
+so the old PUT/POST split is gone); client + bank-account dates → `#inst` for EDN-safe
+session; the **blank-address** trap recurs (empty Contact address posts blank fields →
+all-nil db/id-less map → "tempid used only as value") — same `blank-address?` drop as
+Phase 9. A long detour confirmed the REPL is direct-link-poisoned: validate migrations
+against a fresh `TEST_SERVER_PORT=… lein run -m auto-ap.test-server` JVM, not the REPL.
+
+**Verification:** full e2e suite **71/71** (65 prior + 6 client-wizard: new dialog +
+timeline; edit prefill w/ disabled code; bank-accounts card + add affordance; editor
+open/discard; accept-merge; edit→save round-trip). Engine flow + accept + pass-through +
+edit init also confirmed at the REPL.