feat(transactions): port manual bank-transaction import to SSR

Implement the SSR/alpine/htmx manual transaction import, wiring the
already-declared but unhandled ::external-import-page/parse/import routes.
Mirrors the SSR ledger import: paste the exact master-branch Yodlee
positional-column TSV, review parsed rows in an editable grid with per-row
error/warning badges, and import. Every master validation is preserved and
the existing import.transactions engine is reused unchanged
(via import.manual/import-batch), so core components are untouched.

- New ns auto-ap.ssr.transaction.import (page, paste/parse, editable grid,
  two-tier validation, import handler) + admin-only transactions Import nav.
- Two-tier validation: fixable problems (bad date/amount, unknown client or
  bank-account code, missing fields) are hard errors that block the whole
  batch; inherent skip-conditions (non-POSTED, before start-date/locked,
  already-imported) are warnings computed from the engine's own
  categorize-transaction so the grid preview matches the import result.
- Tests: failing-first Playwright e2e (e2e/transaction-import.spec.ts) plus
  unit/integration coverage (ssr/transaction/import_test.clj, 10 tests).
- Deterministic bank-account code in the e2e seed.

Plan: docs/plans/2026-06-01-001-feat-manual-transaction-import-ssr-plan.md

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

src/clj/auto_ap/ssr/components/aside.clj

@@ -304,6 +304,12 @@
                                 :hx-boost "true"
                                 :hx-include "#transaction-filters"}
                                "Approved")
+                 (when (is-admin? (:identity request))
+                   (menu-button- {:href (bidi/path-for ssr-routes/only-routes
+                                                       ::transaction-routes/external-import-page)
+                                  :active? (= ::transaction-routes/external-import-page (:matched-route request))
+                                  :hx-boost "true"}
+                                 "Import"))
                  (when (can? (:identity request)
                              {:subject :transaction :activity :insights})
                    (menu-button- {:href (bidi/path-for ssr-routes/only-routes