Member invites, gallery resync, content and operator docs

- Invite flow: admin issue/revoke on join requests, public single-use
  claim links (hash-only tokens, 7-day expiry, no state reveal), claim
  creates the Member account and marks the request accepted
- Gallery: admin status page plus resync endpoint; sync refreshes
  thumbnails whose content changed; tools/gallery contract and checker
- Docs: public content page, admin-only operator runbook, api.md
  invite/gallery sections, all routes in the live API docs, docs
  reachability gate test
- Screenshots cover the new pages; version 1.0.18

molodetz/schemas/admin.py

@@ -10,6 +10,14 @@ class AdminIndexOut(OutModel):
     open_joins: int = 0
     user_count: int = 0
     deleted_count: int = 0
+    flyer_count: int = 0
+    meme_count: int = 0
+
+
+class GalleryStatusOut(OutModel):
+    flyers: int = 0
+    memes: int = 0
+    missing: list[str] = []
 
 
 class AdminPostsOut(OutModel):

molodetz/schemas/joins.py

@@ -16,7 +16,16 @@ class JoinRequestOut(OutModel):
     link_title: str | None = None
     link_status: str | None = None
     created_at: str | None = None
+    invite_open: bool = False
+    invite_expires_at: str | None = None
 
 
 class JoinListOut(OutModel):
     requests: list[JoinRequestOut] = []
+
+
+class InvitePageOut(OutModel):
+    valid: bool = False
+    username: str = ""
+    email: str = ""
+    email_locked: bool = False