Task: Investigate RFL complexity root cause

Analyze the root cause of Clang and MSVC compilation failures related to reflect-cpp complexity in ClientManagerTrades.cpp and propose a permanent resolution strategy.

• Root cause for Clang's "expression nesting limit" identified.
• Root cause for MSVC's "C1202" identified.
• Permanent resolution strategy (Triple Isolation) proposed.
• Investigation report published.

• Analyze compiler error logs from failed CI runs.
• Review reflect-cpp internal headers for complexity drivers.
• Map the domain types (trade, trade_instrument) to the failure points.
• Research history of previous workarounds in the codebase.
• Synthesize findings into a formal report.

• Identified that rfl::internal::no_duplicate_field_names is the O(N²) driver.
• Identified that trade_instrument variant is the primary complexity source.
• Discovered that previous workarounds were reverted prematurely.

• Investigation: MSVC C1202 and rfl complexity
• Strategy: TU split + Two-phase parse + Global Clang limits.
• Upstream issue reflect-cpp #350 opened.