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

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, 5 insertions, 1 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/roster.py b/packages/meshbay-node/src/meshbay_node/roster.py
index 80bf16d..8144373 100644
--- a/packages/meshbay-node/src/meshbay_node/roster.py
+++ b/packages/meshbay-node/src/meshbay_node/roster.py
@@ -54,6 +54,10 @@ CODE_LEN = 8                      # 8 × 5 bits = 40 bits of entropy
 # node-wide lockout.
 DEFAULT_INVITE_TTL = 7 * 24 * 3600   # seconds — member invitations
 DEFAULT_PAIR_TTL = 24 * 3600         # seconds — operator pairing
+# An invitation link is a bearer secret that may travel through any messaging
+# service, so its lifetime is fixed rather than the operator's setting: the
+# hub clamps its ticket to the same seven days.
+LINK_INVITE_TTL = 7 * 24 * 3600
 # A device-add code is read off one screen and typed into another, in one
 # sitting. An hour is comfort, not security: the code is bound to the requesting
 # keys by its hash, so a longer window widens nothing an attacker can use.
@@ -1109,7 +1113,7 @@ class Roster:
         return code
 
     async def create_link_invite(
-        self, group_id: str, created_by: str, ttl: int = DEFAULT_INVITE_TTL,
+        self, group_id: str, created_by: str, ttl: int = LINK_INVITE_TTL,
     ) -> tuple[str, str, str]:
         """
         Issue a code bound to no account: `(code, invite_id, expires_at)`.