Enforce HLIL teardown order and clear bridge cache on client shutdown

[themuffinator]

Motivation

• Reproduce HLIL-observed resource teardown ordering so character profiles are freed only after dependent resources are released.
• Ensure shutdown diagnostics and bridge cache handling match expected behavior when BotShutdownClient is called for inactive slots.
• Improve code consistency by adding commented function headers and consistent tab indentation.
• Prevent stale bridge snapshots from persisting after client shutdown by clearing cached updates for the client slot.

Description

• Reordered client resource teardown in BotState_FreeResources to free chat state, weapon weights, then item weights before freeing the character via AI_FreeCharacter and updated bookkeeping slots accordingly.
• Changed BotShutdownClient to emit a clearer warning message and call Bridge_ClearClientSlot for already-shutdown clients, preserving the BLERR_AICLIENTALREADYSHUTDOWN return value.
• Added commented header blocks above functions (e.g. BotState_ResetCombat, BotState_FreeResources, BotState_AttachCharacter, etc.) and normalized indentation to tabs in src/botlib/interface/bot_state.c.
• Left bridge cache clearing behavior intact following normal shutdown by ensuring Bridge_SetClientActive and Bridge_ClearClientSlot are invoked in BotShutdownClient.

Testing

• No automated tests were executed for this change (no test run requested).

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Codex Task