[action] [PR:844] [BMC] Fix bmcctld startup race and honor admin_status on air-cooled boot

[mssonicbld]

Fix bmcctld startup race and honor admin_status on air-cooled boot

Description

1. sync HOST_STATE and seed CHASSIS_MODULE admin_status dedup before starting the BmcEventHandler thread;
   add BmcEventHandler.seed_chassis_module_admin_status() so CONFIG SubscriberStateTable replays are treated as already handled.
2. For non-liquid-cooled platforms, gate automatic startup power_on on CONFIG admin_status=up and skip power_on if admin_status=down. Update run() docstring and add unit tests for seed/dedup, startup ordering and admin-down skip paths.

Motivation and Context

1. bmcctld start can enqueue ACTION_POWER_ON from CONFIG replay before HOST_STATE init and action-loop readiness; CLI changes are logged as "initiating ..." but may never reach "Executing action ...". With a single action-loop consumer, an early or stuck power_on blocks subsequent CLI-driven actions until bmcctld restart.
2. Also fix air-cooled boot ignoring if CONFIG_DB has admin_status=down.

How Has This Been Tested?

run() order is init_host_state() -> seed_chassis_module_admin_status() ->
event thread -> boot sequence -> action loop. Dedup seed records the current CONFIG admin_status so replay does not enqueue ACTION_POWER_ON. Non-liquid OFFLINE boot checks get_switch_host_admin_status() and skips power_on unless admin is up.

Additional Information (Optional)

New unit tests cover CONFIG replay dedup after seed, HOST_STATE init before event thread, non-liquid skip when admin_status=down, and non-liquid power_on when admin_status=up. Nokia H6-128 BMC verified: first-install CLI shutdown/startup works without pmon restart; BMC reboot with admin down leaves Switch-Host powered off.

Signed-off-by: Sonic Build Admin sonicbld@microsoft.com

[mssonicbld]

Original PR: sonic-net/sonic-platform-daemons#844

[mssonicbld]

/azp run

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