Add RSA extraction bootstrap and working notes

docs/case_studies/whetstone_dsl_extraction_yield_snapshot.md

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+# WhetstoneDSL Extraction Yield Snapshot
+
+## Slice
+
+Parser:
+
+- `tools/extract_gate_rows.py`
+
+Contracts:
+
+- `semantic/rsa_gate_extraction_contracts_v0.json`
+
+Input slice:
+
+- first 50 run directories under
+  `CLionProjects/whetstone_DSL/logs/taskitem_runs`
+
+Output:
+
+- `semantic/extracted_gate_rows_slice.ndjson`
+
+## Summary
+
+Observed counts from the 50-run slice:
+
+- runs processed: `50`
+- tasks processed: `106`
+- rows emitted: `424`
+- rows with rejection flags: `330`
+
+Per-gate emitted rows:
+
+- `prereq_op_selector`: `106`
+- `target_file_selection`: `106`
+- `acceptance_command_selection`: `106`
+- `required_tool_selection`: `106`
+
+Per-gate rejected rows:
+
+- `prereq_op_selector`: `12`
+- `target_file_selection`: `106`
+- `acceptance_command_selection`: `106`
+- `required_tool_selection`: `106`
+
+## Dominant Rejection Flags
+
+- `sibling_uniform_target_files`: `106`
+- `sibling_uniform_acceptance_commands`: `106`
+- `sibling_uniform_required_tools`: `106`
+- `invalid_prerequisite_values:whetstone_generate_taskitems,whetstone_queue_ready,whetstone_validate_taskitem`: `12`
+
+## Interpretation
+
+### `prereq_op_selector`
+
+This is the strongest current extraction surface.
+
+It survives most of the slice cleanly, and the rejection cases are informative
+rather than noisy. The rejected rows come from schema-drift runs where
+`prerequisiteOps` was contaminated with tool ids such as:
+
+- `whetstone_generate_taskitems`
+- `whetstone_queue_ready`
+- `whetstone_validate_taskitem`
+
+That means the parser is catching real label pollution rather than inventing
+false negatives.
+
+### `target_file_selection`
+
+Present explicitly, but not yet trustworthy as broad supervision in this slice.
+
+The dominant issue is sibling-uniform output: all tasks in a run often carry the
+same target-file list, which makes naive extraction look more like template
+reuse than local bounded choice.
+
+### `acceptance_command_selection`
+
+Present explicitly, but also highly template-like in this slice.
+
+The same sibling-uniform pattern appears across runs, which suggests these rows
+should remain review-gated until we either:
+
+- find more diverse artifact families
+- or factor the decision more tightly
+
+### `required_tool_selection`
+
+Same current status as acceptance commands.
+
+The field exists and is easy to parse, but the observed slice suggests strong
+template carryover rather than high-confidence local decision variance.
+
+## Immediate Conclusion
+
+The current first supervised RSA gate should be:
+
+- `prereq_op_selector`
+
+The following remain promising, but should stay review-gated or filtered more
+aggressively before broader extraction:
+
+- `target_file_selection`
+- `acceptance_command_selection`
+- `required_tool_selection`
+
+## Next Steps
+
+1. Tighten parser-side filtering for schema-drift prereq rows and optionally
+   split accepted vs rejected outputs.
+
+2. Search for artifact families with higher local variance for:
+   - `target_file_selection`
+   - `acceptance_command_selection`
+   - `required_tool_selection`
+
+3. Promote `prereq_op_selector` to the first extraction-ready gate dataset.