Module termination 

Graceful termination management for Lambda timeout detection.

This module provides TerminationManager which proactively detects approaching Lambda timeouts and signals the runtime to flush checkpoints and return a PENDING response before the Lambda hard-kills the process.

Requirements

• 5.1: wait_for_timeout resolves when deadline - safety_margin is reached
• 5.2: On timeout, flush batcher and return PENDING
• 5.3: Handler completes normally when no timeout
• 5.4: Default safety margin is 5 seconds
• 5.5: Immediate resolution when remaining < margin

Structs

TerminationManager

Manages graceful termination before Lambda timeout.