feat: implement linting and testing

.pre-commit-config.yaml

@@ -0,0 +1,43 @@
+repos:
+  # ── Python: ruff (lint + format) ─────────────────────────────────────────
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.9.9
+    hooks:
+      - id: ruff
+        args: [--fix]
+      - id: ruff-format
+
+  # ── YAML / JSON / Markdown: prettier ─────────────────────────────────────
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: v4.0.0-alpha.8
+    hooks:
+      - id: prettier
+        types_or: [yaml, json, markdown]
+        exclude: |
+          (?x)^(
+            dbt/target/|
+            dbt/dbt_packages/|
+            \.venv/
+          )
+
+  # ── SQL: sqlfluff ─────────────────────────────────────────────────────────
+  - repo: https://github.com/sqlfluff/sqlfluff
+    rev: 3.4.0
+    hooks:
+      - id: sqlfluff-lint
+        additional_dependencies: [sqlfluff-templater-dbt, dbt-core, dbt-postgres]
+      - id: sqlfluff-fix
+        additional_dependencies: [sqlfluff-templater-dbt, dbt-core, dbt-postgres]
+        stages: [manual] # only run sqlfluff-fix manually (make lint-fix)
+
+  # ── General hygiene ───────────────────────────────────────────────────────
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-json
+      - id: check-merge-conflict
+      - id: mixed-line-ending
+        args: [--fix=lf]