feat(cli): chat — Tier 2 check on the signing device, interactive room

Each message's signing device is checked against the group's roster as the
page checks it (a port of transport-roster.js, held to it by the parity
test): chains of countersignatures walked from each account's roots, the
keys accepted per account and node kept in the store, the roster read again
once before a key is called changed. Only "changed" is said, under the
message; --json carries every verdict.

chat with no group opens the interactive chat: the groups, then one group's
conversation IRC-style with pushed messages arriving live and a line to
write in; Esc or /part goes back to the groups, /quit or Ctrl+Q quits. Like
the bare command, it opens on the sign-in screen when nothing is stored.

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

1 files changed, 14 insertions, 0 deletions

diff --git a/packages/meshbay-cli/src/meshbay_cli/client/account.py b/packages/meshbay-cli/src/meshbay_cli/client/account.py
index 9bb85ce..96483e9 100644
--- a/packages/meshbay-cli/src/meshbay_cli/client/account.py
+++ b/packages/meshbay-cli/src/meshbay_cli/client/account.py
@@ -162,6 +162,8 @@ class Account:
             "known_browser": r.get("known_browser") or previous.get("known_browser"),
             # A node's key does not depend on who signed in.
             "pins": previous.get("pins", {}) if previous.get("hub") == self.hub.url else {},
+            "account_pins": (previous.get("account_pins", {})
+                             if previous.get("hub") == self.hub.url else {}),
         }
         if same_account and previous.get("browser_access"):
             state["browser_access"] = previous["browser_access"]
@@ -341,6 +343,18 @@ class Account:
     def pepper_version(self) -> int:
         return int(self.secrets.get("pepper_version") or 1)
 
+    # The device keys this machine accepted for each account, per node (Tier 2,
+    # `roster.py`): public keys, kept with the other pins. Losing them costs one
+    # "first sight", never a wrong answer.
+
+    def account_pins(self, node_pk: str, user_id: str) -> list[str] | None:
+        return self.state.get("account_pins", {}).get(node_pk, {}).get(user_id)
+
+    async def set_account_pins(self, node_pk: str, user_id: str, keys: list[str]) -> None:
+        def put(state: dict, secrets: dict) -> None:
+            state.setdefault("account_pins", {}).setdefault(node_pk, {})[user_id] = keys
+        await self.update(put)
+
     def pin(self, node_id: str) -> str | None:
         return self.state.get("pins", {}).get(node_id)