feat: invitation links no longer bound to an e-mail address

A link is redeemable by whoever opens it first, so it can be sent by any
messaging app. The address is optional (mail + label only); a link lives
7 days, fixed. Adds a Share button; see MESHBAY_DESIGN.md §3.4.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/db/models.py b/packages/meshbay-hub/src/meshbay_hub/db/models.py
index 51a3d47..09eb437 100644
--- a/packages/meshbay-hub/src/meshbay_hub/db/models.py
+++ b/packages/meshbay-hub/src/meshbay_hub/db/models.py
@@ -151,12 +151,12 @@ class GroupInviteLink(Base):
 
     A link carries two secrets. The node's code decides whether someone gets the
     group key, and the hub never sees it. This row decides whether someone may
-    *reach* the node at all — membership, which is all the hub has to give — and
-    only for the account whose verified address matches `email_hash`. The ticket
-    is stored as `sha256(ticket)`, so a copy of this table opens nothing.
+    *reach* the node at all — membership, which is all the hub has to give — for
+    the first account that redeems it. The ticket is stored as `sha256(ticket)`,
+    so a copy of this table opens nothing.
 
-    No address in the clear: `email_hash` is the same blind index `users` has,
-    and `email_masked` is what the owner's list shows (`al***@ex***.com`).
+    The address is optional and binds nothing: when the inviter gave one,
+    `email_masked` is what the owner's list shows (`al***@ex***.com`).
     """
     __tablename__ = "group_invite_links"
 
@@ -164,8 +164,7 @@ class GroupInviteLink(Base):
     group_id:       Mapped[str] = mapped_column(ForeignKey("groups.id"), nullable=False)
     created_by:     Mapped[str] = mapped_column(ForeignKey("users.id"), nullable=False)
     ticket_hash:    Mapped[str] = mapped_column(String(64), nullable=False)
-    email_hash:     Mapped[str] = mapped_column(String(64), nullable=False)
-    email_masked:   Mapped[str] = mapped_column(String(128), nullable=False)
+    email_masked:   Mapped[str | None] = mapped_column(String(128))
     # The node's handle for its half, so cancelling can take back both.
     node_invite_id: Mapped[str] = mapped_column(String(32), nullable=False, default="")
     created_at:     Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now)