Bump version to 3.6.0

Release 3.6.0. Highlights since 3.5.3:
- New estimator: LPDiD (Local Projections DiD; Dube, Girardi, Jorda &
  Taylor 2025), exported from the top-level package with full API docs.
- PlaceboTests: new optional `treatment` param on placebo_group_test,
  fake-group path now filters ever-treated by default, and
  permutation_test reports the (1+count)/(B+1) randomization-inference
  p-value.
- ~78-84% peak-memory reduction in the multiplier-bootstrap estimators
  (Callaway-Sant'Anna, EfficientDiD, HeterogeneousAdoptionDiD) via
  block-tiled weight generation.
- Methodology validation promoted to Complete: TwoStageDiD, PlaceboTests,
  Survey Data Support.
- Security: pyo3 + numpy 0.28 -> 0.29 (RUSTSEC-2026-0176/0177); deps and
  CI hardening (blas-src, checkout v7, release-build guard).
- Numerous perf and rank-deficiency correctness fixes across linalg,
  imputation, two-stage, conley, spillover, and continuous DiD.

Promotes the CHANGELOG [Unreleased] section to [3.6.0] - 2026-06-29 and
syncs the version across __init__.py, pyproject.toml, rust/Cargo.toml,
llms-full.txt, and CITATION.cff.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: igerber

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.6.0] - 2026-06-29
+
 ### Added
 - **`LPDiD` (Local Projections Difference-in-Differences; Dube, Girardi, Jordà & Taylor 2025,
   *J. Applied Econometrics* 40(5):741-758).** Per-horizon long-difference OLS
@@ -1794,6 +1796,7 @@ for the full feature history leading to this release.
 [2.1.2]: https://github.com/igerber/diff-diff/compare/v2.1.1...v2.1.2
 [2.1.1]: https://github.com/igerber/diff-diff/compare/v2.1.0...v2.1.1
 [2.1.0]: https://github.com/igerber/diff-diff/compare/v2.0.3...v2.1.0
+[3.6.0]: https://github.com/igerber/diff-diff/compare/v3.5.3...v3.6.0
 [3.5.3]: https://github.com/igerber/diff-diff/compare/v3.5.2...v3.5.3
 [3.5.2]: https://github.com/igerber/diff-diff/compare/v3.5.1...v3.5.2
 [3.5.1]: https://github.com/igerber/diff-diff/compare/v3.5.0...v3.5.1

CITATION.cff

@@ -7,8 +7,8 @@ authors:
     family-names: Gerber
     orcid: "https://orcid.org/0009-0009-3275-5591"
 license: MIT
-version: "3.5.3"
-date-released: "2026-06-25"
+version: "3.6.0"
+date-released: "2026-06-29"
 doi: "10.5281/zenodo.19646175"
 url: "https://github.com/igerber/diff-diff"
 repository-code: "https://github.com/igerber/diff-diff"

diff_diff/__init__.py

@@ -301,7 +301,7 @@
 DCDH = ChaisemartinDHaultfoeuille
 HAD = HeterogeneousAdoptionDiD
 
-__version__ = "3.5.3"
+__version__ = "3.6.0"
 __all__ = [
     # Estimators
     "DifferenceInDifferences",

diff_diff/guides/llms-full.txt

@@ -2,7 +2,7 @@
 
 > A Python library for Difference-in-Differences causal inference analysis. Provides sklearn-like estimators with statsmodels-style output for econometric analysis.
 
-- Version: 3.5.3
+- Version: 3.6.0
 - Repository: https://github.com/igerber/diff-diff
 - License: MIT
 - Dependencies: numpy, pandas, scipy (no statsmodels dependency)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "diff-diff"
-version = "3.5.3"
+version = "3.6.0"
 description = "Difference-in-Differences causal inference with sklearn-like API. Callaway-Sant'Anna, Synthetic DiD, Honest DiD, event studies, parallel trends."
 readme = "README.md"
 license = "MIT"

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "diff_diff_rust"
-version = "3.5.3"
+version = "3.6.0"
 edition = "2021"
 rust-version = "1.85"
 description = "Rust backend for diff-diff DiD library"