[AIP-94] airflowctl command migration #68402

Body

Goal: move every remote airflow CLI command (anything backed by a public REST API endpoint)
into airflowctl. Admin commands have no API and are local-only. They run components (scheduler,
api-server, triggerer, dag-processor, kerberos, standalone), manage the DB, or reach internals
directly (DAG parsing/rendering, local provider manager). Those remain in the airflow CLI and are
out of scope here.

Why:
AIP-81: Enhanced Security in CLI via Integration of API
and its sub-proposal
AIP-94: Decouple Remote Commands from the airflow CLI.

Status: converted. The only work per command now is to add the marker decorator to the
listed commands so they are frozen for development. There is no airflowctl migration to
do.

What to do:

• Add the marker decorator to each command on the list. See PR Convert CLI Deprecations to maintainer idetifiable only #68726 for how the
  decorator is converted to a maintainer and developer facing marker (it replaces the
  user facing deprecation warning). Apply that same decorator to each command.
• The decorator is maintainer and developer facing only. It records the airflowctl
  equivalent and adds a note in the code, and it does not print anything to users or
  change behavior.
• The point of the marker is to freeze these commands for development. Once a command is
  marked, no new features or behavior changes should land on it.

Admin (no API, local-only, not migrated, stay in the airflow CLI):

• dags: show, show-dependencies, test, reserialize (parse/render DAGs directly)
• tasks: test, render (execute/render DAG files directly)
• providers: links, widgets, hooks, triggers, behaviours, logging, secrets,
  executors, queues, notifications, configs, lazy-loaded, auth-managers (read the local
  provider manager)

dags

• dags trigger [AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175
• dags delete [AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175
• dags list
• dags details [AIP-94] Migrate airflow dags details to the API server #68529
• dags state
• dags list-runs
• dags list-jobs
• dags list-import-errors [AIP-94] Mark dags list-import-errors as migrated to airflowctl #68602
• dags report
• dags clear
• dags pause
• dags unpause
• dags next-execution

tasks

• operations for tasks
• tasks state
• tasks states-for-dag-run
• tasks clear
• tasks list
• tasks failed-deps

assets

• assets materialize ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)
• assets list [AIP-94] Add deprecation marker to assets list/details cli commands #68531
• assets details [AIP-94] Add deprecation marker to assets list/details cli commands #68531

pools

• pools: list / get / set / delete / import / export ([AIP-94] Create a CLI airflowctl client and adopt it in existing commands #68175)

variables

• variables list [AIP-94] Mark variables CLI commands as migrated to airflowctl #68932
• variables get [AIP-94] Mark variables CLI commands as migrated to airflowctl #68932
• variables set [AIP-94] Mark variables CLI commands as migrated to airflowctl #68932
• variables delete [AIP-94] Mark variables CLI commands as migrated to airflowctl #68932
• variables import [AIP-94] Mark variables CLI commands as migrated to airflowctl #68932

connections

• connections list [AIP-94] Mark connections commands as migrated to airflowctl #68972
• connections add [AIP-94] Mark connections commands as migrated to airflowctl #68972
• connections delete [AIP-94] Mark connections commands as migrated to airflowctl #68972
• connections import [AIP-94] Mark connections commands as migrated to airflowctl #68972
• connections test [AIP-94] Mark connections commands as migrated to airflowctl #68972
• connections create-default-connections [AIP-94] Mark connections commands as migrated to airflowctl #68972

backfill

• backfill create

jobs

• jobs check

config

• config get-value [AIP-94] Mark config CLI commands as migrated to airflowctl #68958
• config list [AIP-94] Mark config CLI commands as migrated to airflowctl #68958

providers

• providers list [AIP-94] Migrate airflow providers command to the API server #68525
• providers get [AIP-94] Migrate airflow providers command to the API server #68525

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.