PHASE2_IMPLEMENTATION_PLAN.md

The plan outlines a phased approach for MVP to ambitious features, starting with a 5-7 day MVP deployment, based on research and decision memos. PHASE2_IMPLEMENTATION_PLAN.md provides go/no-go recommendation and effort analysis for Phase 2 file types processing PHASE2_SCOPE_DECISION.md includes PHASE2_IMPLEMENTATION_PLAN.md as part of the Phase 2 research outputs. Phase 2 research outputs include PHASE2_IMPLEMENTATION_PLAN.md as part of the documentation. Sonnet 4.6 created the PHASE2_IMPLEMENTATION_PLAN.md containing the go/no-go recommendation and effort versus value analysis. The PHASE2_UNIFIED_STRATEGY.md and PHASE2_IMPLEMENTATION_PLAN.md documents contain complementary research outputs informing Phase 2 implementation decisions.