Executors not stored to database when they terminate

Description

When an executor terminates (e.g., RunnableStatus.TERMINATED with CloseType.EARLY_STOP), it is not automatically stored to the database. Executors are only persisted when the bot shuts down gracefully via the stop command.

Current Behavior

• StoreExecutorAction exists in hummingbot/strategy_v2/models/executor_actions.py but is never emitted by any controller
• store_executor() method exists in ExecutorOrchestrator but is never called during normal operation
• Executors are only saved via store_all_executors() which is called on bot shutdown

Expected Behavior

When an executor terminates (status changes to TERMINATED), it should automatically be stored to the database so that:

1. Users can analyze completed executors without stopping the bot
2. Data is not lost if the bot crashes or is force-killed
3. Export/analysis scripts can access completed executor data in real-time

Steps to Reproduce

1. Start an LP Rebalancer controller
2. Wait for an executor to complete (e.g., rebalance or early stop)
3. Check the Executors table in SQLite - it will be empty
4. The executor shows as TERMINATED in the Hummingbot CLI but is not in the database

Proposed Solution

Controllers should emit StoreExecutorAction when an executor terminates. This could be done in:

1. Controller level: Each controller emits StoreExecutorAction when it detects an executor has terminated
2. Orchestrator level: ExecutorOrchestrator automatically stores executors when their status changes to TERMINATED

Option 2 is cleaner as it handles all executor types centrally.

Affected Components

• hummingbot/strategy_v2/executors/executor_orchestrator.py
• hummingbot/strategy_v2/controllers/controller_base.py
• All controllers that manage executors

Workaround

Run stop command in Hummingbot CLI to flush all executors to the database before analyzing.