Closes#19534 (security).
A worker spawned by the kanban dispatcher has HERMES_KANBAN_TASK set
to its own task id. The destructive tools (kanban_complete,
kanban_block, kanban_heartbeat) resolved task_id via
_default_task_id() which preferred an explicit arg over the env var,
with no ownership check — so a buggy or prompt-injected worker could
complete / block / heartbeat any OTHER task (sibling, cross-tenant,
anything) by supplying its id. Reporter's repro: worker for t_A
passed task_id=t_B to kanban_complete and got {"ok": true}.
Fix: add _enforce_worker_task_ownership(tid). If HERMES_KANBAN_TASK
is set and tid doesn't match, return a structured tool error with
guidance to use kanban_comment (for information handoff across tasks)
or kanban_create (for follow-up work). Orchestrator profiles (no env
var, but kanban toolset enabled per #18968) are exempt — their job
is routing and sometimes includes closing out child tasks.
Kept unrestricted (deliberately):
- kanban_show — workers legitimately read parent/sibling handoff context
- kanban_comment — cross-task comments are the handoff mechanism
- kanban_create — orchestrator fan-out, worker follow-up spawning
- kanban_link — parent/child linking
Tests: 5 new regression tests in tests/tools/test_kanban_tools.py
covering the grid (worker-attacks-foreign ×3 tools, worker-own-task
preserved, orchestrator-unrestricted). 36/36 pass.
The _check_kanban_mode() gating function only checked for
HERMES_KANBAN_TASK env var, which is only set by the dispatcher
when spawning workers. This prevented orchestrator profiles (like
techlead) from using kanban_create, kanban_link, etc. even when
they had 'kanban' explicitly in their toolsets config.
Now uses load_config() from hermes_cli.config (which has mtime-based
caching) to check if 'kanban' is in the profile's toolsets list.
This enables orchestrators to route work via Kanban while workers
continue using the dispatcher env var.
Fixes#18968
