feat: 0.5.3 breadth-first RE plan and signal-gated orch/ELT fan-out

[RichardHightower]

Bring DEKC reverse-engineering to parity with SAC 0.5.6’s plan → ranked task list → signal-gated specialist fan-out, without replacing DEKC’s LoopPolicy or adversarial judges.

What landed

• dekc_plan.py — deterministic BFS map of scan roots + optional Fabric/PBI/inventory exports. Writes .dekc/re-plan.md / .json / progress. mark / show for checklist done/blocked.
• dekc_orchestrate.py --plan-only / --from-plan --area (same flags on dekc_walk.py). Unattended orchestrate plans first, then captures only domains the plan detected.
• /dekc-plan skill + command. Orchestrators (data-lake-walker, reverse-engineering-orchestrator) teach: plan → spawn listed producers → existing skeptics → re-adversary-judge.
• Signal-gated specialists: airflow-scout, glue-job-scout, fabric-pipeline-scout, thin ADF / Step Functions / Composer / cron scouts, dbt-elt-scout, duckdb-scout, notebook-scout, dq-scout. No Airflow markers → no Airflow scout.
• Walk gaps: cheap capture for DuckDB, .ipynb SQL cells, Delta _delta_log, orchestration IngestionJob stubs, DQ markers (GE / Soda / dbt tests — no runtime).
• Query-time data-retriever stays separate. No live Glue/S3/Fabric APIs. SAC still owns CI/CD (Actions that only trigger Glue/dbt are a cross-link note).

How to run plan-then-fan-out

export SECOND_BRAIN_IDENTITY=claude-code/lumenfield-detector

# 1. Breadth-first plan (no capture)
python3 scripts/dekc_orchestrate.py \
  --repo . --system "Retail Lake" --scan-root tests/fixtures/re-plan-lake \
  --export tests/fixtures/re-plan-lake/exports/fabric-items.json \
  --plan-only --json

# 2. Review knowledge/.dekc/re-plan.md — spawn only listed specialists

# 3. Scoped capture per area
python3 scripts/dekc_orchestrate.py \
  --repo . --scan-root tests/fixtures/re-plan-lake \
  --from-plan knowledge/.dekc/re-plan.json --area lake
python3 scripts/dekc_plan.py mark \
  --plan knowledge/.dekc/re-plan.json --area lake --item capture --status done

# 4. Existing adversarial close (unchanged)
python3 scripts/dekc_grade.py --repo . --bundle knowledge
# then lineage-skeptic / business-skeptic / stream-job-skeptic / re-adversary-judge

Standalone plan: python3 scripts/dekc_plan.py --scan-root <mirror> --write --json

Tests

python3 tests/test_dekc_plan.py
python3 tests/test_dekc.py
python3 -m py_compile scripts/dekc_*.py

Fiction fixtures only (tests/fixtures/re-plan-lake, re-plan-sql-only). SQL-only tree does not list airflow-scout.

Merge note

Please merge as a merge commit (not squash) so the 0.5.3 changelog / version bump stay a single visible merge on main.