diff --git a/.dev-kit b/.dev-kit
new file mode 160000
index 0000000..646f903
--- /dev/null
+++ b/.dev-kit
@@ -0,0 +1 @@
+Subproject commit 646f903ef30dd44f07c0481b67d63507f703411e
diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..b24b4e2
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,45 @@
+# .editorconfig — Shared editor settings for TaxCloud repos.
+#
+# Installed by .dev-kit/install.sh as .editorconfig in the repo root.
+# Most editors (VS Code, JetBrains, vim, etc.) respect this natively
+# or via plugin. See https://editorconfig.org
+#
+# Like .gitattributes, this is committed and applies to all contributors.
+
+root = true
+
+# Default: 2-space indent, UTF-8, LF, trim trailing whitespace
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+# Makefiles require tabs
+[Makefile]
+indent_style = tab
+
+[*.mk]
+indent_style = tab
+
+# Awk: tabs (idiomatic)
+[*.awk]
+indent_style = tab
+
+# Go: tabs (gofmt standard)
+[*.go]
+indent_style = tab
+
+# Shell scripts: 4-space indent (Google style, widely adopted)
+[*.sh]
+indent_size = 4
+
+# YAML: 2-space (standard)
+[*.{yml,yaml}]
+indent_size = 2
+
+# Markdown: preserve trailing whitespace (line breaks)
+[*.md]
+trim_trailing_whitespace = false
diff --git a/.gitattributes b/.gitattributes
index 82b7f42..89d2b37 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,10 +1,114 @@
-# Exclude dev/CI files from git archive (GitHub release ZIPs)
-.gitignore export-ignore
-.gitattributes export-ignore
-.github/ export-ignore
-.cursorrules export-ignore
-Test/ export-ignore
-Makefile export-ignore
-run-test.sh export-ignore
-scripts/ export-ignore
-docs/images/ export-ignore
+# .gitattributes — Shared line-ending, diff, and merge settings.
+#
+# Installed by .dev-kit/install.sh as .gitattributes in the repo root.
+# Committed to the repo, so these rules apply to all contributors
+# regardless of their local git config.
+#
+# This file makes core.autocrlf largely irrelevant: the rules below
+# override it on a per-path basis, which is more precise and portable.
+
+# =============================================================================
+# Line Endings
+# =============================================================================
+# Normalize to LF on commit, use platform-native on checkout.
+# This single rule prevents most cross-platform line-ending bugs.
+* text=auto
+
+# Force LF for files that break with CRLF (scripts, configs, Makefiles).
+# A Windows checkout with CRLF in a shell script is a runtime error.
+*.sh text eol=lf
+*.bash text eol=lf
+*.awk text eol=lf
+Makefile text eol=lf
+*.mk text eol=lf
+*.yml text eol=lf
+*.yaml text eol=lf
+*.json text eol=lf
+*.toml text eol=lf
+Dockerfile text eol=lf
+*.dockerfile text eol=lf
+
+# =============================================================================
+# Binary Files
+# =============================================================================
+# Prevent git from applying line-ending conversion or textual merge
+# to files that aren't text. Without these rules, git may corrupt
+# binaries by "fixing" line endings.
+
+# Images
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.webp binary
+*.svg binary
+
+# Fonts
+*.woff binary
+*.woff2 binary
+*.ttf binary
+*.otf binary
+*.eot binary
+
+# Archives
+*.zip binary
+*.tar binary
+*.tar.gz binary
+*.tgz binary
+*.gz binary
+
+# Documents
+*.pdf binary
+
+# Compiled binaries (extensionless)
+# Go, Rust, and C projects typically output to bin/ or dist/.
+# Mark these directories as binary to prevent line-ending corruption.
+bin/** binary
+dist/** binary
+out/** binary
+
+# Other binary formats that lack common extensions
+*.wasm binary
+*.pb binary
+*.pyc binary
+*.so binary
+*.dylib binary
+*.dll binary
+*.exe binary
+
+# =============================================================================
+# Better Diffs
+# =============================================================================
+# Tell git which language driver to use for diff hunk headers.
+# Instead of showing the nearest line, git shows the enclosing
+# function/class name — much easier to orient yourself in a diff.
+*.go diff=golang
+*.py diff=python
+*.rb diff=ruby
+*.html diff=html
+*.htm diff=html
+*.css diff=css
+*.md diff=markdown
+*.markdown diff=markdown
+
+# =============================================================================
+# Lock Files
+# =============================================================================
+# Generated lock files produce huge, unreadable diffs. Suppress the
+# diff output (they still show as changed, just without the noise).
+package-lock.json -diff
+yarn.lock -diff
+pnpm-lock.yaml -diff
+go.sum -diff
+Cargo.lock -diff
+Gemfile.lock -diff
+poetry.lock -diff
+composer.lock -diff
+
+# Merge strategy: lock files should be regenerated, not merged.
+# "ours" keeps the current branch's version; the developer then
+# re-runs the package manager to reconcile.
+package-lock.json merge=ours
+yarn.lock merge=ours
+pnpm-lock.yaml merge=ours
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..c49bc07
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,18 @@
+# Dependabot configuration — generated by .dev-kit/ci/scaffold.sh
+# Source: .dev-kit/ci/templates/dependabot.yml
+# Keeps GitHub Actions and submodules up to date.
+
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    groups:
+      actions:
+        patterns: ["*"]
+
+  - package-ecosystem: gitsubmodule
+    directory: /
+    schedule:
+      interval: weekly
diff --git a/.github/workflows/auto-merge-devkit.yml b/.github/workflows/auto-merge-devkit.yml
new file mode 100644
index 0000000..11e7bf9
--- /dev/null
+++ b/.github/workflows/auto-merge-devkit.yml
@@ -0,0 +1,32 @@
+# Auto-merge .dev-kit submodule updates — generated by .dev-kit/ci/scaffold.sh
+# Source: .dev-kit/ci/templates/auto-merge-devkit.yml
+# Automatically merges Dependabot PRs that bump the .dev-kit submodule
+# after CI passes. Requires Dependabot to be configured (see dependabot.yml).
+
+name: Auto-merge .dev-kit
+
+on: pull_request
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    name: Auto-merge .dev-kit updates
+    if: github.actor == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Dependabot metadata
+        id: meta
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Auto-merge .dev-kit submodule bumps
+        if: steps.meta.outputs.dependency-names == '.dev-kit'
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..e4d1411
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,38 @@
+# CI workflow — generated by .dev-kit/ci/scaffold.sh
+# Source: .dev-kit/ci/templates/ci.yml
+# Runs lint, test, and build on every push and pull request.
+#
+# Relies on standard Make targets from .dev-kit/mk/common.mk.
+# Customize behavior by defining _lint, _test, _build in your Makefile.
+
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ci:
+    name: Lint / Test / Build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Lint
+        run: make lint
+
+      - name: Test
+        run: make test
+
+      - name: Build
+        run: make build
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..2a35cac
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,33 @@
+# Release workflow — generated by .dev-kit/ci/scaffold.sh
+# Source: .dev-kit/ci/templates/release.yml
+# Creates a GitHub release when a version tag is pushed.
+#
+# Tag format: v1.2.3
+
+name: Release
+
+on:
+  push:
+    tags: ['v*']
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    name: Create Release
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Build
+        run: make build
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          generate_release_notes: true
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..5f04e2f
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule ".dev-kit"]
+	path = .dev-kit
+	url = git@github.com:FedTax/.dev-kit.git
diff --git a/Makefile b/Makefile
index 0e055c5..76040c8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,23 +1,18 @@
-.PHONY: test test-local test-unit test-compatibility lint lint-fix help
-
-# Default target
-help:
-	@echo "Available commands:"
-	@echo "  make test              - Run all tests using Docker"
-	@echo "  make test-local        - Run all tests locally (requires PHP)"
-	@echo "  make test-unit         - Run unit tests only"
-	@echo "  make test-compatibility - Run Adobe Commerce 2.4.8-p1 compatibility tests"
-	@echo "  make lint              - Run PHP CodeSniffer linting"
-	@echo "  make lint-fix          - Auto-fix linting issues where possible"
-	@echo "  make help              - Show this help message"
-
-# Run all tests using Docker
-test:
+include .dev-kit/mk/common.mk
+
+.PHONY: _test _lint test-local test-unit test-compatibility lint-fix
+
+# --------------------------------------------------------------------------
+# Standard interface implementations
+# --------------------------------------------------------------------------
+
+##@ Testing
+
+_test: ## Run all tests using Docker
 	@echo "Running all tests with Docker..."
 	@./run-test.sh
 
-# Run tests locally (requires PHP)
-test-local:
+test-local: ## Run all tests locally (requires PHP)
 	@echo "Running all tests locally..."
 	@vendor/bin/phpunit Test/Unit/ --testdox
 	@for test_file in Test/Integration/*.php; do \
@@ -25,18 +20,17 @@ test-local:
 		php "$$test_file"; \
 	done
 
-# Run unit tests only
-test-unit:
+test-unit: ## Run unit tests only
 	@echo "Running unit tests..."
 	@vendor/bin/phpunit Test/Unit/ --testdox
 
-# Run Adobe Commerce 2.4.8-p1 compatibility tests
-test-compatibility:
+test-compatibility: ## Run Adobe Commerce 2.4.8-p1 compatibility tests
 	@echo "Running Adobe Commerce 2.4.8-p1 compatibility tests..."
 	@php Test/Integration/AdobeCommerce248p1CompatibilityTest.php
 
-# Run PHP CodeSniffer linting
-lint:
+##@ Code Quality
+
+_lint: ## Run PHP CodeSniffer linting
 	@echo "Running PHP CodeSniffer..."
 	@lint_output=$$(phpcs --standard=PSR2 --extensions=php Model/ Observer/ Logger/ Setup/ --ignore=Test/ 2>&1 || true); \
 	if echo "$$lint_output" | grep -q "FOUND [1-9][0-9]* ERROR"; then \
@@ -48,7 +42,6 @@ lint:
 		echo "$$lint_output"; \
 	fi
 
-# Auto-fix PHP CodeSniffer issues where possible
-lint-fix:
+lint-fix: ## Auto-fix PHP CodeSniffer issues where possible
 	@echo "Auto-fixing PHP CodeSniffer issues..."
 	@phpcbf --standard=PSR2 --extensions=php Model/ Observer/ Logger/ Setup/ --ignore=Test/