fix(kanban): keep graph tools orchestrator-only

[mosaiq-systems]

Summary

• make kanban_create and kanban_link orchestrator-only graph-routing tools instead of exposing them to dispatcher-scoped workers
• enforce the same orchestrator boundary inside the handlers, so stale schemas or direct dispatch cannot mutate graph topology from worker scope
• mark environment-sensitive Kanban tool gates as uncached to prevent orchestrator visibility from leaking into later worker schema builds in long-lived processes
• update worker prompt guidance to record follow-up work through comments, completion metadata, or blocking instead of spawning tasks

Tests

• uv run --with pytest --with pytest-asyncio --with pytest-timeout python -m pytest tests/tools/test_kanban_tools.py tests/hermes_cli/test_kanban_db.py -q -o 'addopts=' (244 passed)
• uv run python -m py_compile tools/registry.py tools/kanban_tools.py agent/prompt_builder.py tests/tools/test_kanban_tools.py
• independent review checked the diff for project-specific leakage, local paths, secrets, and cache/gate regressions

[mosaiq-systems]

Closing this PR and replacing it with a sanitized generic Kanban bug-fix PR.