chore: restore pre-commit configuration

Restore .pre-commit-config.yaml that was in original PR but missing from
current branch. This file provides code quality, security scanning, and
formatting validation hooks.

Author: bakerboy448

.pre-commit-config.yaml

@@ -0,0 +1,57 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.4.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-added-large-files
+      - id: check-merge-conflict
+      - id: debug-statements
+      - id: check-executables-have-shebangs
+
+  - repo: https://github.com/psf/black
+    rev: 23.7.0
+    hooks:
+      - id: black
+        language_version: python3
+        args: [--line-length=88]
+
+  - repo: https://github.com/pycqa/flake8
+    rev: 6.0.0
+    hooks:
+      - id: flake8
+        args: [--max-line-length=88, --extend-ignore=E203,W503]
+
+  - repo: https://github.com/pycqa/isort
+    rev: 5.12.0
+    hooks:
+      - id: isort
+        args: [--profile=black]
+
+  - repo: https://github.com/Yelp/detect-secrets
+    rev: v1.4.0
+    hooks:
+      - id: detect-secrets
+        args: ['--baseline', '.secrets.baseline']
+        exclude: |
+          (?x)^(
+              config_template\.json|
+              \.secrets\.baseline
+          )$
+
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.4.1
+    hooks:
+      - id: mypy
+        additional_dependencies: [types-requests]
+        args: [--ignore-missing-imports]
+
+  - repo: local
+    hooks:
+      - id: reddit-config-check
+        name: Check Reddit config safety
+        entry: python -c "import json; config = json.load(open('config.json')) if __import__('os').path.exists('config.json') else {}; exit(1) if not config.get('anonymize_moderators', True) else exit(0)"
+        language: system
+        files: config\.json$
+        pass_filenames: false