refactor(cli): extract goal channel operation owner

[Duang777]

Summary

• move goal-channel prepare-operation and deliver-operation registration and dispatch into a bounded command owner
• keep activation, source-runtime routing, rendering, and exit-code ownership in goal_channel.py
• preserve preview/no-write, execute readback, executor-drift, provider-stage, and unknown-write outcome semantics
• pin both commands to the new owner in the CLI module ownership smoke
• mark GH-C06 as in review on the contributor task board

Source

Implements one cohesive GH-C06 CLI ownership slice from docs/development/contributor-tasks.md, aligned with the S5 Goal Channel boundary in the overall roadmap.

Validation

• 68 passed in tests/extensions/test_lark_goal_channel.py and tests/extensions/test_lark_goal_channel_operation.py
• 65 passed across CLI entrypoint, Goal Channel target/runtime, project lifecycle, and control-plane import-boundary tests
• Ruff format/check passed on all changed Python files
• targeted mypy passed for both command modules with dependency errors silenced
• CLI module ownership smoke passed
• CLI command module regression passed
• docs governance smoke passed
• real prepare-operation --help and deliver-operation --help entrypoints passed
• exact-head loopx canary premerge --from-git-diff passed: 14 selected checks, 0 failures; one inherited advisory remains for unrelated chat_server.py and goal_topic_connections.py module budgets
• public boundary scan passed for all six changed paths

Scope

No frontend or Lark companion change is required: public CLI arguments, packets, routing, and provider behavior are unchanged. The bounded future-facing pass stopped at the operation command owner; broader Goal Channel extraction remains outside this PR.

[Duang777]

CI baseline note: the two failing test shards are the same post-#4771 stale priority assertions that reproduce on main@2caada69d:

• test_a_lane_that_already_declares_a_priority_is_not_relabelled
• test_real_canonical_provider_preserves_complete_complex_todo_semantics

They are isolated in #4819. I will sync this branch with main after #4818 (quota module budget extraction) and #4819 land, then rerun the refactor checks on the resulting exact head.