refactor(structex): delete dead shadowed duplicate modules aragora/types.py and aragora/receipts.py

[scarmani]

Summary

Delete the two dead, shadowed duplicate modules aragora/types.py and aragora/receipts.py (P4a layering foundation; architecture §6 module consolidation map; feature p4a-dead-files).

Both .py files are unreachable because same-named packages shadow them and take import precedence:

• import aragora.types resolves to aragora/types/__init__.py (not the .py)
• import aragora.receipts resolves to aragora/receipts/__init__.py (not the .py)

So deleting the .py files is semantically inert and needs no shim (the packages already take over). Specifically:

• aragora/receipts.py only re-exported DecisionReceipt (from aragora.gauntlet.receipt) and LegacyDecisionReceipt (from aragora.export.decision_receipt). The aragora/receipts/ package already re-exports both (strict superset, plus LaneCompletionReceipt/emit_lane_receipt/etc.).
• aragora/types.py's aliases (AgentName/DebateId/Score) were unreachable behind the aragora/types/ package (which exports the event protocols). No external module imported those aliases (only the deleted file's own docstring referenced them).

ODR conflict check (MANDATORY FIRST STEP) — CLEAN

Re-ran gh pr diff --name-only across all 233 open PRs and explicitly on the 3 open ODR PRs:

• Zero open PR touches aragora/types.py or aragora/receipts.py themselves.
• ODR PRs feat(gauntlet): post-quantum hybrid ODR receipt signing (Ed25519 + ML-DSA-65) #8608 (odr_signing.py + odr_schema.json), feat(odr): in-package ODR verification engine (odr_verify) — ODR-3 server core #8389 (odr_verify.py), feat(compliance): human-oversight attestation records + Art.14/NIST oversight evidence pack (#8230) #8289 (odr_export.py) touch only aragora/gauntlet/ (+ aragora-verify/pyproject/tests) — zero file overlap with this deletion. Pre-cleared per library/operator-approvals.md (orchestrator ODR-gate authorization 2026-06-25); adjacent gauntlet/ activity is explicitly non-blocking.

Validation (fulfills VAL-P4A-007)

$ git ls-files aragora/types.py aragora/receipts.py
(empty)
$ test -z "$(git ls-files aragora/types.py aragora/receipts.py)" && echo PASS
PASS
$ python3 -c "import aragora.types, aragora.receipts; print(aragora.types.__file__); print(aragora.receipts.__file__)"
.../aragora/types/__init__.py
.../aragora/receipts/__init__.py     # exit 0; both resolve to the packages

Local gates (all green): make lint ✓ · ruff format --check ✓ · differential typecheck (new=64 ≤ env-drift 66) ✓ · pytest tests/types tests/receipts tests/export 671 passed ✓ · make test-smoke import canary ✓ · smoke tier 138 passed ✓.

Notes for reviewers

• No shim is intentional and correct here: this is a deletion of dead duplicates, not a move/rename. The old import paths (aragora.types, aragora.receipts) keep working because the packages shadow the deleted files (verified above).
• aragora/module_tiers.yaml is intentionally NOT regenerated in this PR. Deleting types.py recomputes the types module tier (integrated→experimental), but aragora/module_tiers.yaml is path-frozen by open PRs chore(deps): update audit-vulnerable Python locks #8460/fix(ci): clear base security and smoke blockers #8461/feat(tier4): settle_tier4_pr.py — one-command --settle-apply + receipt-backed preapproval gate #8382. The Module Tier Drift workflow is non-required and is already red on main for an unrelated ambient reason (NEW module: missions). Per the documented docs/METRICS.md path-freeze precedent, this drift is left for an orchestrator-coordinated regen that absorbs both items (does not affect the 6 required checks; docs/METRICS.md itself stays within the 0.5% drift tolerance, so it is unchanged).
• Stale .github/CODEOWNERS glob /aragora/types.py @an0mium is left untouched: CODEOWNERS is a @scarmani-pinned Tier-4 merge-authority surface; a dangling glob is harmless (GitHub ignores entries for non-existent paths). Flagged for an operator-owned follow-up.

Risk

Minimal. Deletion of unreachable dead code; import behavior is unchanged (proven by the companion import check + import canary + 671 consumer tests).

[github-actions]

Aragora Code Review

Advisory-only review. No issues found.

[scarmani]

Claude independent model review

Reviewer: claude (anthropic) — independent adversarial model review via the Aragora Claude reviewer, grounded on the exact PR head.
Head: 30801fb (30801fb), committed 2026-06-25T21:30:25Z.
PR: #8633.
Model family: claude

Verdict: PASS

No findings.

dogfood: yes

[scarmani]

Grok independent model review

Reviewer: grok (xai) — independent adversarial model review via Grok Build CLI harness, grounded on the exact PR head.
Head: 30801fb (30801fb), committed 2026-06-25T21:30:25Z.
PR: #8633.
Model family: grok

Verdict: PASS

No findings.

Review notes (non-blocking): Both deleted modules were shadowed by existing packages (aragora/receipts/__init__.py, aragora/types/__init__.py); Python resolves aragora.receipts and aragora.types to those packages, so the .py files were unreachable dead code. DecisionReceipt / LegacyDecisionReceipt re-exports remain intact via the receipts package; no in-repo imports of the removed types.py NewTypes (AgentName, DebateId, etc.); tests/export/test_receipt_contract.py and tests/types/test_protocols.py pass. No security surface change.

dogfood: yes