feat(kanban): expose profile routing hints

[bagelcode-jhkim]

Summary

• Expose profile kanban_worker_model_routing metadata as compact model/runtime hints in the kanban decomposer roster.
• Reuse the same compact hint for dispatcher worker env (HERMES_KANBAN_MODEL_HINT) and optional spawn receipt comments.
• Keep routing metadata best-effort: malformed/missing profile config is ignored and never blocks decomposition or dispatch.

Tests

• RED: ./scripts/run_tests.sh tests/hermes_cli/test_kanban_decompose.py failed before implementation because roster entries lacked model_hint.
• GREEN: ./scripts/run_tests.sh tests/hermes_cli/test_kanban_decompose.py tests/hermes_cli/test_kanban_core_functionality.py → 177 passed, 0 failed.
• python3 -m py_compile hermes_cli/kanban_db.py hermes_cli/kanban_decompose.py tests/hermes_cli/test_kanban_decompose.py tests/hermes_cli/test_kanban_core_functionality.py
• git diff --check

Review

• Independent review found no blockers/high/medium issues.
• Follow-up low notes addressed by normalizing public helper inputs and bounding/single-lining free-form hint values.

[bagelcode-jhkim]

Closing: this change is being kept as a local Hermes patch for Joohyun instead of upstreaming to NousResearch/hermes-agent.