refactor(ssr): revert hiccup→Selmer migration; render forms in Hiccup again

Abandons the Selmer-templating step of the SSR re-authoring and moves the four
migrated form/wizard modals back to Hiccup (com/* components), keeping the
whole-form HTMX swap doctrine, top-rooted render functions, and the
session-backed wizard engine unchanged.

- transaction/edit, transaction/bulk_code, invoices (bulk-edit group), and
  pos/sales_summaries render via com/* again; every hx-* swap (whole-form +
  targeted location-cell / totals-tbody / inline account-cell swaps) is
  preserved exactly.
- add com/single-modal-card to centralize the md:w-[950px] md:h-[650px] modal
  chrome that previously lived only in the Selmer modal-card templates.
- delete auto-ap.ssr.selmer, auto-ap.ssr.components.selmer, selmer_test, the
  whole resources/templates tree (55 files), the selmer dependency, and the
  tailwind resources/templates content glob.
- strip Selmer guidance from the ssr-form-migration skill + modernization plan.

Verified: all four namespaces compile and render with no stringified-hiccup
leaks; output.css rebuilds byte-identically (no Tailwind class loss); 60 e2e
specs pass — the four reverted modals (incl. whole-form-swap focus/caret tests)
plus the untouched wizard/pay/new/rule modals.

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

test/clj/auto_ap/ssr/selmer_test.clj

@@ -1,36 +0,0 @@
-(ns auto-ap.ssr.selmer-test
-  (:require
-   [auto-ap.ssr.selmer :as sut]
-   [clojure.string :as str]
-   [clojure.test :refer [deftest is testing]]
-   [hiccup2.core :as h2]))
-
-(deftest hiccup->html
-  (testing "renders a Hiccup form to an HTML string"
-    (is (= "<span class=\"label\">A &amp; B</span>"
-           (sut/hiccup->html [:span.label "A & B"])))))
-
-(deftest selmer-embeds-hiccup
-  (testing "a Hiccup component renders inside a Selmer template via |safe"
-    (let [frag (sut/hiccup->html [:span.badge "from hiccup"])
-          out  (sut/render-str "<div>{{frag|safe}}</div>" {:frag frag})]
-      (is (str/includes? out "<span class=\"badge\">from hiccup</span>"))
-      ;; without |safe the markup would be escaped; |safe keeps it verbatim
-      (is (not (str/includes? out "&lt;span"))))))
-
-(deftest selmer-fragment-inside-hiccup
-  (testing "a Selmer fragment renders inside a Hiccup tree without double-escaping"
-    (let [sel (sut/render-str "<a href=\"{{url}}\">{{label}}</a>" {:url "/x" :label "Go"})
-          out (str (h2/html {} [:div (sut/raw sel)]))]
-      (is (= "<div><a href=\"/x\">Go</a></div>" out)))))
-
-(deftest render-file-from-classpath
-  (testing "render-file resolves a template under resources/templates and keeps plain-HTML Alpine/HTMX attrs"
-    (let [out (sut/render "templates/interop-smoke.html"
-                          {:title "Interop OK"
-                           :hiccup_frag (sut/hiccup->html [:span.badge "from hiccup"])})]
-      (is (str/includes? out "Interop OK"))
-      (is (str/includes? out "from hiccup"))
-      ;; plain-HTML attributes (the whole point of Selmer) survive unambiguously
-      (is (str/includes? out "x-model=\"value.value\""))
-      (is (str/includes? out "tippy?.show()")))))