REQ-CONFIG-007: land canonical M4 PopulationConfig defaults and close Q-002 #549

Goal

Complete the remaining M4 configuration slice for permanent REQ-CONFIG-007 after Drive HANDOFF-REPAIR-M4-003 resolved Q-002. Land the canonical M4 PopulationConfig defaults/ownership vocabulary, preserve the already-implemented DefinitionRegistry.needCategories projection, close repository Q-002, and promote the composite requirement only when the full acceptance evidence is earned.

Evidence

• Drive authority: HANDOFF-REPAIR-M4-003 / Handoff/03 §8 now defines the complete M4 PopulationConfig baseline and ownership rules.
• MACHINE mirror sync spec: sync specification mirror from Drive #548 is on current master 203fe92cc928c37453ad18e24d8976378caef565; mirrored Handoff/03 contains the repaired defaults/ownership rules.
• Repository docs/spec/OPEN_QUESTIONS.md still has Q-002 OPEN and describes sixteen controls as intentionally undefined.
• Authoritative docs/spec/implementation_status.csv still records REQ-CONFIG-007 as PARTIAL from the earlier declaration/validation/needCategories projection slice.

Canonical M4 PopulationConfig baseline to implement exactly:

• minHouseholdCashPerCapita = 2.5
• liquidityFloorShare = 0.10
• baseParticipationByStratum = { VULNERABLE: 0.70, WORKING_MIDDLE: 0.70, AFFLUENT: 0.70 }
• minParticipation = 0.40
• maxParticipation = 0.90
• minHealthParticipationFactor = 0.75
• maxHealthParticipationFactor = 1.02
• minWeakOpportunityFactor = 0.90
• maxWeakOpportunityFactor = 1.05
• wageSignalAdjustmentSpeed = 0.20
• maxWageSignalStep = ln(1.05)
• essentialAlpha = 0.25
• incomeAlpha = 0.15
• employmentAlpha = 0.20
• prosperityAlpha = 0.15
• scenarioRealIncomeScale = 10
• healthRecoveryRate = 0.05
• healthMaintenanceThreshold = 0.85
• serviceHealthRate = 0.02
• serviceBaseline = 0.50

Ownership rules: PopulationConfig.baseParticipationByStratum is authoritative for the M4 participation path and supersedes LaborConfig.baselineParticipationRate there; population health-participation bounds are distinct from labor health-productivity bounds; worker-equivalent tolerance remains SimulationConfig.numeric.quantityEpsilon; P_raw weights remain fixed formula constants; NeedCategoryDefinition owns per-category substitution/target/budget/carryover data; stale parallel aliases (needSubstitutionElasticity, consumptionBudgetShare*, precautionaryCashFloorMonths, healthEmaAlpha, wageSignalAlpha) must not be revived; prosperityEmaAlpha maps to prosperityAlpha=0.15.

Scope

• Update createDefaultSimulationConfig() / PopulationConfig defaults to the exact twenty values above.
• Keep existing validators strict; add focused canonical-value regressions and sensitive negative controls where needed.
• Preserve existing DefinitionRegistry.needCategories projection/genesis behavior and prove it still survives.
• Rewrite repository Q-002 to ANSWERED with HANDOFF-REPAIR-M4-003 provenance and the canonical ownership resolution.
• Reconcile the existing REQ-CONFIG-007 ledger row truthfully; PARTIAL is correct until all composite acceptance is proved. Promote only with earned evidence and normal post-merge provenance handling.
• Regenerate docs/spec/IMPLEMENTATION_STATUS.md from the authoritative CSV when the ledger changes.

Non-goals

• No REQ-POPULATION-001..003 behavior implementation in this unit.
• No M5 trade/FX, M6 fiscal/Clan dynamics, M7 monetary dynamics, M8 demography/migration, or later-milestone pull-forward.
• No laborEpsilon, no second participation owner, no duplicate need-substitution control, and no M8 defaults.
• Do not patch docs/spec/mirror/; it is MACHINE-owned.

Acceptance criteria

1. All twenty canonical M4 PopulationConfig defaults equal the Handoff/03 §8 HANDOFF-REPAIR-M4-003 values, including exact Math.log(1.05) semantics for maxWageSignalStep.
2. Existing validation accepts the canonical defaults without widening ranges; focused tests pin the values and protect ownership/alias boundaries.
3. Existing needCategories DefinitionPack → DefinitionRegistry → WorldState projection remains intact with regression evidence.
4. Q-002 is ANSWERED and no repository text still claims the sixteen repaired controls are intentionally undefined.
5. Deferred M8 demography/migration/mobility controls remain absent from the M4 default slice.
6. REQ-CONFIG-007 evidence is truthful and six-column-valid; no premature merge SHA or false completion claim.
7. TypeScript typecheck/tests/build and retained .NET gates pass on the exact PR head; policy/ledger checks pass.
8. PR handoff names every changed artifact and exact tested head, then stops at the production→judgement boundary for SLOPSTER.

Verification

Run the focused config/default/projection tests plus the repository-required TypeScript and retained .NET gates. Verify scripts/implementation_status.py --check if evidence files change. Confirm the final PR diff contains no mirror edits and no population behavior/M5+ scope.