fix(kanban): preserve dashboard completion summaries

[LeonSGP43]

Fixes #20008

Summary

• prompt for a completion summary before dashboard Done transitions from detail, drag/drop, or bulk actions
• forward bulk dashboard result/summary/metadata into complete_task instead of dropping them
• add hermes kanban edit <task_id> --result ... to backfill completed task results and update the latest completed run summary for audit/context recovery

Scope

This stays inside the Kanban dashboard/API/CLI result path. It does not change dispatcher claim semantics or task completion rules outside already-supported Done transitions.

Verification

• scripts/run_tests.sh tests/plugins/test_kanban_dashboard_plugin.py::test_bulk_status_done_forwards_completion_summary tests/plugins/test_kanban_dashboard_plugin.py::test_dashboard_done_actions_prompt_for_completion_summary tests/hermes_cli/test_kanban_core_functionality.py::test_cli_edit_backfills_result_on_done_task tests/hermes_cli/test_kanban_core_functionality.py::test_cli_edit_rejects_non_done_task -> 4 passed
• env -u WEIXIN_TOKEN -u WEIXIN_ACCOUNT_ID -u WEIXIN_HOME_CHANNEL -u WEIXIN_HOME_CHANNEL_NAME -u WEIXIN_HOME_CHANNEL_THREAD_ID scripts/run_tests.sh tests/plugins/test_kanban_dashboard_plugin.py tests/hermes_cli/test_kanban_core_functionality.py::test_cli_complete_with_summary_and_metadata tests/hermes_cli/test_kanban_core_functionality.py::test_cli_edit_backfills_result_on_done_task tests/hermes_cli/test_kanban_core_functionality.py::test_cli_edit_rejects_non_done_task tests/hermes_cli/test_kanban_core_functionality.py::test_cli_bulk_complete_with_summary_rejects tests/hermes_cli/test_kanban_core_functionality.py::test_cli_bulk_complete_without_summary_still_works tests/hermes_cli/test_kanban_core_functionality.py::test_completed_event_payload_carries_summary -> 61 passed
• python -m py_compile hermes_cli/kanban.py hermes_cli/kanban_db.py plugins/kanban/dashboard/plugin_api.py
• git diff --check

[teknium1]

Merged via PR #20195 (commit 354502e). Your commit was cherry-picked onto current main with your authorship preserved in git log. Nice scope — both the prompt-on-Done flow for the dashboard AND a proper kanban edit recovery path, with the bulk API correctly threading the result/summary/metadata fields. Good clean test coverage too.

#20195