Sprint 003 findings + Sprint 004 pipeline decision audit plan

- split_prereq_op_dataset.py: extract accepted/rejected/schema-drift rows per gate
- gen_prereq_op_rsa_data.py: convert accepted rows to Fabricate TSV format
- 1000-run extracted dataset: 1297 accepted prereq_op rows, 24 schema-drift
- Key finding: needs_validate_intake always True; effective gate is binary
  (needs_resolve_dependencies 77%, needs_architect_review 20%)
- Key finding: run corpus text is template-driven (17 unique inputs) — not
  suitable for text-based training; RSA exists before ideal input is available
- ROADMAP: gate lifecycle framing — goal is choice of backend, not forced
  determinism; RSA operates on imperfect/mixed/incomplete input by design
- training_data_strategy.md: taskitem-as-self-contained-work-unit constraint
- SPRINT-003: updated with 1000-run results, text audit findings, design constraints
- SPRINT-004: pipeline decision audit — manual walkthrough of every decision
  from project description to generated artifact; execute next session

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ROADMAP.md

@@ -322,17 +322,33 @@ It should not be allowed to overfit the library to one memory-management ontolog
 - add packaging and runtime loading
 - add diagnosis and recommendation APIs on top of benchmark evidence
 
+## Gate Lifecycle — The Fundamental Property
+
+RSA gates exist **before ideal input is available**. The intake may return a mix of
+structured and unstructured data, or incomplete directions. That is the design
+requirement, not a defect to fix upstream.
+
+The RSA layer gives operators **choice of backend** per gate: statistical model,
+deterministic rules, SLM, LLM, or human escalation. As the contract matures, more
+backend options become viable. Some gates may remain statistical models indefinitely
+because that is the right fit. Others may be replaced by rules. The operator decides.
+
+Abstain and escalation policies are first-class responses to weak input — not failure
+modes. A gate that correctly abstains on incomplete input is working as designed.
+
 ## Phase 5: Whetstone Integration
 
 - Expose WhetstoneDSL gates through the library.
 - Replace selected MCP bounded decisions with local specialist calls.
 - Log abstentions and misroutes for retraining and gate redesign.
+- For each deployed gate: track which backend is active and what would justify switching.
 
 ## Phase 6: Hivemind Integration
 
 - Feed gate failure data into Hivemind as entropy evidence.
 - Use Hivemind to prioritize which high-entropy gates deserve deterministic tooling.
 - Distinguish "needs a bigger model" from "needs a better tool or schema."
+- Support backend substitution per gate without changing the gate contract.
 
 ## Exit Criteria For Version 0