refactor(ssr): full Selmer migration of Transaction Edit; remove the wizard

Migrate every part of the Transaction Edit modal's HTML to Selmer templates
(zero Hiccup in the render path) and delete the mm multi-modal "wizard"
abstraction entirely -- there was only ever one step.

- New auto-ap.ssr.components.selmer (sc) + ~22 shared component partials under
  resources/templates/components/ (typeahead, button-group, radio-card,
  data-grid, validated-field, modal, buttons, inputs, SVGs). Each wrapper renders
  its own partial; dynamic HTMX/Alpine attrs bridge via attrs->str -> {{attrs|safe}}.
- 15 modal templates under resources/templates/transaction-edit/.
- Delete EditWizard/LinksStep records + all mm/* usage. Plain handlers: flat
  wrap-decode-edit (fields renamed off step-params[...], stray keys stripped),
  flat wrap-derive-state, *errors*-based field errors, generic wrap-form-4xx-2.
- Drop the edit-wizard-navigate route (routes ~12 -> 5).
- Fix: stray `method` (tab button-group hidden) leaked into the upsert -> 500;
  strip decoded map to schema keys.
- e2e selectors updated (#wizard-form->#edit-form, #wizardmodal->#editmodal,
  step-params[...] field names). Parity: swap 6/6, edit 8/8, suite 38/1
  (1 pre-existing unrelated nav test).
- ssr-form-migration skill updated with the learnings (composition mechanics,
  sc/* library, drop-the-wizard recipe, scorecard row, 3 new gotchas).

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

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

@@ -13,9 +13,13 @@ implement the multi-step protocol (`mm/ModalWizardStep` + friends), serialize an
 snapshot into hidden fields, and register 10–20 stacked-middleware routes — all for one
 step. That is pure overhead to delete.
 
+> **Done — Transaction Edit is now a plain form.** `LinksStep`/`EditWizard` and all `mm/*`
+> usage were deleted from `transaction/edit.clj`; the worked example below is realized, not
+> aspirational. See "Single-step → plain form (realized)".
+
 ## The machinery being replaced
 
-`transaction/edit.clj` today still carries the old shape, useful as the "before":
+The old shape (kept here as the "before"):
 
 ```clojure
 (defrecord LinksStep [linear-wizard]
@@ -49,6 +53,33 @@ A `?mode=` toggle is just the `GET` re-rendering with a different query param
 plain form. An add-row interaction is one extra `POST` that appends a fresh row and
 re-renders (the `+1` route).
 
+### Single-step → plain form (realized: Transaction Edit)
+
+What replacing the wizard actually looked like, end to end:
+
+1. **Delete the records + middleware.** `EditWizard`/`LinksStep`, `mm/open-wizard-handler`,
+   `mm/next-handler`, `mm/submit-handler`, `mm/wrap-wizard`, `mm/wrap-decode-multi-form-state`,
+   and the `edit-wizard-navigate` route all go. `render-step` becomes a plain `render-form`.
+2. **Rename the fields off `step-params[...]`.** Field names are now the schema path
+   directly (`(path->name2 :transaction/accounts 0 :transaction-account/account)` →
+   `transaction/accounts[0][transaction-account/account]`). They decode straight into the
+   form schema via the unchanged `wrap-nested-form-params` + `mc/decode` — no two-key
+   snapshot/step-params decode. **Strip stray keys after decode** (`select-keys` to the
+   schema's keys) or a non-schema input like the tab group's `method` hidden 500s the save
+   (see `gotchas.md`).
+3. **Flat state.** `wrap-derive-state` builds a plain `{:snapshot :edit-path :step-params}`
+   map (not the `MultiStepFormState` record): `entity-only` fields from the entity, editable
+   fields from the live posted form (absent = cleared). The ~34 `:snapshot` reads keep
+   working.
+4. **Validation/error flow without `wrap-ensure-step`.** Reuse the generic
+   `wrap-form-4xx-2` directly: `(-> submit-edit (wrap-form-4xx-2 render-form-response) …)`.
+   `submit-edit` runs `assert-schema` then dispatches the save; on a throw, `wrap-form-4xx-2`
+   re-renders the whole form with `:form-errors` keyed by schema paths. A `*errors*` dynamic
+   var (bound by `render-form`) replaces the form-cursor's `*form-errors*` for field lookups.
+5. **Routes shrink to** `edit-wizard` (GET open), `edit-submit` (POST), `edit-form-changed`
+   (POST whole-form re-render for dependent changes), `location-select` (GET),
+   `unlink-payment` (POST).
+
 ---
 
 ## Genuinely multi-step → data-driven engine with session-stored step state