Add lint + reload-trigger workflow

Validates YAML/required fields/duplicate ids/requirement types with
yq+jq against the exact shape content.rs parses (not a full schema
check - that would mean building portal just to lint content), then
publishes portal.content.reload over NATS so every running portal
instance picks up the change without a restart (portal's own
content::watch_for_reload, added alongside this).

lint.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+# Validates every question YAML file's shape against what
+# portal/src/content.rs actually requires at parse time - not a full
+# schema check (that would mean building portal itself just to lint
+# content, real coupling for no real benefit here), but the mistakes
+# that would actually break a load: bad YAML, missing `id`/`name`,
+# duplicate `id`s, and unknown requirement `type`s. Uses `yq` (the
+# jq-wrapping kislyuk/yq, not the Go mikefarah/yq) so every check is a
+# real jq filter, not bespoke parsing.
+set -euo pipefail
+
+dir="${1:-questions}"
+fail=0
+declare -A seen_ids
+
+shopt -s nullglob
+for f in "$dir"/*.yaml; do
+	if ! json=$(yq . "$f" 2>&1); then
+		echo "FAIL $f: invalid YAML: $json" >&2
+		fail=1
+		continue
+	fi
+
+	id=$(jq -r '.id // empty' <<<"$json")
+	name=$(jq -r '.name // empty' <<<"$json")
+
+	if [[ -z "$id" ]]; then
+		echo "FAIL $f: missing required 'id'" >&2
+		fail=1
+	elif [[ -n "${seen_ids[$id]:-}" ]]; then
+		echo "FAIL $f: duplicate id '$id' (also used by ${seen_ids[$id]})" >&2
+		fail=1
+	else
+		seen_ids[$id]="$f"
+	fi
+
+	if [[ -z "$name" ]]; then
+		echo "FAIL $f: missing required 'name'" >&2
+		fail=1
+	fi
+
+	# "textarea" and "file" are the two values content.rs special-cases;
+	# anything else is passed straight through as an HTML <input type>
+	# attribute, so this is the real set of valid values, not a guess.
+	bad_types=$(jq -r '
+		[.alternatives[]?.features[]?.requirements[]?
+			| select(.type != null and (.type | IN(
+				"text", "textarea", "file", "email", "tel", "url", "number",
+				"password", "date", "datetime-local", "time", "month", "week",
+				"color", "range", "checkbox", "radio", "hidden", "search"
+			) | not))
+			| .type]
+		| unique | .[]
+	' <<<"$json")
+	if [[ -n "$bad_types" ]]; then
+		echo "FAIL $f: unknown requirement type(s): $(tr '\n' ' ' <<<"$bad_types")" >&2
+		fail=1
+	fi
+done
+
+if [[ $fail -eq 0 ]]; then
+	echo "OK: all question files valid"
+fi
+exit $fail