Bump version to 3.11.0

[igerber]

Summary

• Bump version 3.10.0 → 3.11.0 across pyproject.toml, diff_diff/__init__.py, rust/Cargo.toml, diff_diff/guides/llms-full.txt, and CITATION.cff (version + date-released: 2026-08-29).
• Roll the CHANGELOG [Unreleased] section to [3.11.0] - 2026-08-29 and add the comparison link. Headline material: the DMLDiD estimator family (Chang 2020) — DML infrastructure (feat: DML infrastructure - cross-fitting, shared DR scores, ridge, learner protocol (PR-B0) #789), staggered panel ATT(g,t) (feat(dml): DMLDiD estimator - Chang (2020) staggered panel ATT(g,t) (DML PR-B1) #793), repeated cross sections (feat(dml): DMLDiD panel=False repeated cross sections - Chang (2020) Case 2 (DML PR-B2) #794), survey-design/cluster support (feat(dml): DMLDiD survey-design and cluster support on both lanes (DML survey PR) #796) — plus the DML follow-up fix sweep (fix: summary-alpha guard sweep, zero-SE plot gate, lambda-slope dedup, shared pscore_trim validator (DML follow-ups) #795).
• Extend the test_naming_guard _NEXT_RELEASE ladder with (3, 11): "4.0" (interim minors keep the 4.0 enforcement horizon) so the version-keyed Duty C lifecycle gate re-arms at the new version.
• Pre-release: release-build-check run 33247407917 passed on main (2026-08-29).

Methodology references (required if estimator / math changes)

• Method name(s): N/A - no methodology changes (version metadata only)
• Paper / source link(s): N/A
• Any intentional deviations from the source (and why): None

Validation

• Tests added/updated: tests/test_naming_guard.py ladder entry; test_naming_guard + test_v4_matrix + test_guides pass locally (354 passed). Note: test_allowlists_are_reachable fails under a local py3.9 venv on clean main too (pre-existing PEP 649 attribution difference; the CI leg that runs it uses 3.14 and passes) — unrelated to this bump.
• Backtest / simulation / notebook evidence (if applicable): N/A

Security / privacy

• Confirm no secrets/PII in this PR: Yes

[github-actions]

Overall assessment: ✅ Looks good

Executive summary

• No estimator, weighting, variance, identification, or default behavior changed.
• Version metadata is consistent across Python, Rust, packaging, citation, and guide surfaces.
• The naming lifecycle guard correctly preserves the 4.0 enforcement horizon.
• One P2 changelog-maintenance issue remains.
• Automated tests could not run because pytest is unavailable; syntax and TOML validation passed.

Methodology

No findings. No methodology-bearing code changed, so paper/Registry reconciliation is not applicable.

Code Quality

No findings.

Performance

No findings.

Maintainability

No findings.

Tech Debt

No findings.

Security

No findings or exposed secrets detected.

Documentation/Tests

P2 — Release cut leaves changelog references stale

• Location: CHANGELOG.md:L8, CHANGELOG.md:L2597, CHANGELOG.md:L3957, CHANGELOG.md:L3995, CHANGELOG.md:L4039, CHANGELOG.md:L4047, CHANGELOG.md:L4093
• Impact: Renaming the only [Unreleased] heading makes several references point to a nonexistent or incorrect section and leaves contributors without the changelog target described in CONTRIBUTING.md.
• Concrete fix: Add a fresh empty ## [Unreleased] section and comparison link, then replace references inside the 3.11.0 notes with “this 3.11.0 release section” or similarly accurate wording.

[github-actions]

🔁 AI review rerun (requested by @igerber)

Head SHA: c58bcd0e341964a7a992d195ac3bf94f14ab7d24

---

Overall assessment: ✅ Looks good

Executive summary

• The prior changelog P2 is resolved: [Unreleased] remains available above the new 3.11.0 section.
• No estimator, inference, weighting, assumptions, or defaults changed.
• Version metadata is consistent across Python, Rust, packaging, citation, and guides.
• The naming guard correctly maps 3.11 to the 4.0 enforcement horizon.
• Static syntax/TOML/CFF validation passed; tests could not run because pytest is unavailable.

Methodology

No findings. The diff contains no methodology-bearing changes requiring paper reconciliation.

Code Quality

No findings.

Performance

No findings.

Maintainability

No findings.

Tech Debt

No findings.

Security

No findings or exposed secrets detected.

Documentation/Tests

No findings. The previous changelog issue is addressed at CHANGELOG.md:L8-L10. The 3.11 comparison link is present at CHANGELOG.md:L5472.