feat: 添加公开内容相关API接口及测试用例

backend/tests/tenant_public.http

@@ -0,0 +1,36 @@
+@host = http://localhost:8080
+@tenantCode = 2s
+
+# NOTE:
+# - tenant_public endpoints do NOT require tenant membership.
+# - Auth is optional: provide a token to get accurate has_access for paid contents.
+@token = eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoyLCJpc3MiOiJ2MiIsImV4cCI6MTc2NjYzMzAyMSwibmJmIjoxNzY2MDI4MjExfQ.RjLVil6EnbPi4LMPyVBzR2vFaeXelypk5fKInsAzqc8
+
+### Tenant Public - Contents list (published + public), guest
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents?page=1&limit=10
+Content-Type: application/json
+
+### Tenant Public - Contents list (published + public), optional auth
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents?page=1&limit=10
+Content-Type: application/json
+Authorization: Bearer {{ token }}
+
+### Tenant Public - Content detail (published + public), guest
+@contentID = 1
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents/{{ contentID }}
+Content-Type: application/json
+
+### Tenant Public - Preview assets (role=preview), guest
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents/{{ contentID }}/preview
+Content-Type: application/json
+
+### Tenant Public - Main assets (role=main), guest
+# Rule confirmed: public + price=0 => guest can access main assets.
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents/{{ contentID }}/assets
+Content-Type: application/json
+
+### Tenant Public - Main assets (role=main), optional auth (paid content requires purchase/owner)
+GET {{ host }}/t/{{ tenantCode }}/v1/public/contents/{{ contentID }}/assets
+Content-Type: application/json
+Authorization: Bearer {{ token }}
+