fix(ssr): humanize the client wizard's required-field message

A missing required field (e.g. the Info step with no Location added) surfaced
Malli's raw "missing required key". Override the missing-key message in
validate-with's me/humanize call so it reads "This is required." for every
required field across the client wizard. Verified live on the Info step.

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

src/clj/auto_ap/ssr/admin/clients.clj

@@ -491,12 +491,19 @@
 
 (defn- decode-info [request] (->edn-safe-dates (decode-with info-schema request)))
 
+(def ^:private humanize-opts
+  "Friendlier text for a missing required field than Malli's default
+   \"missing required key\" (e.g. the Info step with no location added)."
+  {:errors (assoc-in me/default-errors
+                     [:malli.core/missing-key :error/message]
+                     "This is required.")})
+
 (defn- validate-with
   "Per-step validation: a step can't advance until its fields satisfy the step schema.
    Returns a humanized errors map or nil."
   [schema data _request]
   (when-not (mc/validate schema data)
-    (me/humanize (mc/explain schema data))))
+    (me/humanize (mc/explain schema data) humanize-opts)))
 
 (defn- client-timeline [active]
   (let [steps ["Info" "Matches" "Contact" "Bank Accounts" "Integrations" "Cash Flow" "Other Settings"]