[codex] Add optional staged lifecycle stack

[LimiNode]

Summary

• add the optional lifecycle::ILifecycleModule contract for owner-loop modules with process(), idempotent shutdown(), and terminal is_stopped()
• add a non-owning lifecycle::LifecycleStack that processes dependencies forward and shuts dependents down one stage at a time in reverse registration order
• integrate MarketDataRouter and BaseTradingPlatform with the common lifecycle interface while preserving their direct APIs
• keep startup explicit because platform run(bool), component initialize(), and application bot startup do not share one semantic contract
• add a runnable Router integration example and synchronized canonical English/Russian lifecycle guides

Lifecycle Contract

• register lower-level dependencies first and dependents last, for example platform -> router -> bot
• process() runs forward through modules that still participate in the current stage
• shutdown() starts with the last dependent and does not request shutdown of the next lower module until the current module reports is_stopped()
• lower-level executors keep processing while asynchronous dependents drain
• module references are non-owning and must outlive the stack and its complete shutdown
• the stack is owner-loop confined, creates no thread, owns no retry/timeout policy, and does not call shutdown from its destructor
• use is optional; direct platform, Router, bot, and node lifecycle calls remain supported

Router Integration

• MarketDataRouter::is_stopped() maps to its existing is_shutdown_complete() state
• a stack registered as platform -> router keeps the platform owner loop alive until late subscribe/unsubscribe completions and Router physical cleanup finish
• failed Router cleanup deliberately keeps the stack non-terminal until the application applies its existing retry policy

Documentation

• guides/lifecycle-stack.md: canonical English contract
• guides/lifecycle-stack.ru.md: synchronized Russian contract
• README, AGENTS, project overview, platform/API guides, implementation notes, build guide, and both Router guides link or summarize the new API

Verification

• lifecycle_stack_test: 3 passed
• market_data_router_test: 21 passed
• market_data_subscriber_base_test: 15 passed
• lifecycle_event_safety_test: 8 passed
• header_only_odr_test: 4 passed
• lifecycle_stack_example: ran successfully and drained a deferred routed unsubscribe
• project header guard scan: 224 guarded files, bad=0, duplicates=0
• modified Markdown local-link smoke: 39 file links, missing=0
• paired lifecycle guide structure: 7 sections and 16 code fences in each language
• git diff --check

Local MinGW compilation used -Wa,-mbig-obj for large umbrella translation units.

Stack

Depends on #155 (refactor/market-data-router-implementation).