Add vendor pre-population for bulk code and individual edit forms

- Add vendor-changed HTMX handlers for both bulk code and individual edit
- Pre-populate default account at 100% when vendor is selected and no accounts exist
- Fix render-accounts-section to render from step-params correctly
- Change bulk code vendor-changed from hx-get to hx-post to include form data
- Add routes for vendor-changed endpoints
- Update e2e tests to cover vendor pre-population
- Run lein cljfmt fix across codebase

src/cljc/auto_ap/routes/admin/vendors.cljc

@@ -13,5 +13,4 @@
              "/new" {:get ::new}
              "/merge" {:get ::merge
                        :put ::merge-submit}
-             ["/" [#"\d+" :db/id] "/edit"] {:get ::edit
-                                            }})
+             ["/" [#"\d+" :db/id] "/edit"] {:get ::edit}})