feat: support multi-user Discord threads via context var

- Add contextvars.ContextVar to carry resolved peer name from
  pre_gateway_dispatch to Honcho session init without modifying
  event.user_id (auth uses raw Discord snowflake)
- _pre_gateway_dispatch: now stores resolved peer in context var
- _patched_do_session_init: reads context var first, falls back
  to kanban resolution, then to existing user_id

Requires thread_sessions_per_user: true in profile config.yaml
(added to ashley, claire, finn, matt, paul)

__init__.py

@@ -10,6 +10,7 @@ Config: /opt/data/identity-config.json (persistent volume)
 
 from __future__ import annotations
 
+import contextvars
 import json
 import logging
 import os
@@ -23,6 +24,12 @@ logger = logging.getLogger(__name__)
 
 CONFIG_PATH = Path("/opt/data/identity-config.json")
 
+# Context var to carry resolved peer name from pre_gateway_dispatch
+# to Honcho's _do_session_init without modifying event.user_id.
+_resolved_peer_var: contextvars.ContextVar[str | None] = contextvars.ContextVar(
+    "identity_resolved_peer", default=None
+)
+
 # ── Config ──────────────────────────────────────────────────────────────────
 
 
@@ -161,10 +168,22 @@ _original_init: Callable | None = None
 def _patched_do_session_init(self, cfg, session_id: str, **kwargs):
     """Wrapper around Honcho's _do_session_init.
 
-    If no user_id was provided by the gateway (kanban worker / CLI context),
+    Priority for user_id:
-    resolve one from the identity config and inject it.
+    1. _resolved_peer_var from pre_gateway_dispatch (gateway multi-user)
+    2. get_peer_name() for kanban workers
+    3. kwargs.get("user_id") as-is (existing Discord snowflake fallback)
     """
-    if not kwargs.get("user_id"):
+    # Check context var first (set by _pre_gateway_dispatch for
+    # gateway-originated messages — peer name already resolved)
+    resolved = _resolved_peer_var.get()
+    if resolved:
+        logger.info(
+            "identity: Honcho peer '%s' from gateway dispatch (was %s)",
+            resolved, kwargs.get("user_id", "(none)"),
+        )
+        kwargs["user_id"] = resolved
+    elif not kwargs.get("user_id"):
+        # Kanban worker / CLI — no user_id set by gateway
         resolved = get_peer_name()
         if resolved:
             logger.info(
@@ -222,13 +241,17 @@ def _apply_honcho_patch():
 
 
 def _pre_gateway_dispatch(event: Any, gateway: Any, session_store: Any, **kw) -> dict | None:
-    """Log resolved peer identity before dispatch."""
+    """Resolve peer identity and store it for Honcho session init."""
     platform = getattr(event, "platform", "unknown")
     user_id = getattr(event, "user_id", "unknown")
     resolved = resolve_peer(platform, user_id)
 
     if resolved:
-        logger.debug("identity: gateway platform=%s user_id=%s → peer=%s", platform, user_id, resolved)
+        logger.debug(
+            "identity: gateway platform=%s user_id=%s → peer=%s",
+            platform, user_id, resolved,
+        )
+        _resolved_peer_var.set(resolved)
     else:
         logger.info("identity: unmapped gateway user platform=%s user_id=%s", platform, user_id)
     return None