feat(ci): add strict HTML, CSS, and JS pre-commit checkers

Three new pre-commit hooks (all PyPI-installable, language: python):

djlint-check — HTML formatter consistency
  Runs djlint --check so any future hand-edits that deviate from djlint's
  canonical HTML formatting are caught before commit.
  Configuration additions in pyproject.toml:
    profile = "html"   — enables the full HTML5 rule set
    indent = 2         — enforces 2-space indentation
    max_line_length = 120 — matches the Python project limit
    format_js = false  — prevents djlint from mangling JS regex tokens
    format_css = false — CSS is intentionally minified; keep it verbatim

check-embedded-css (scripts/check_css.py + tinycss2==1.5.1)
  Extracts every <style> block from HTML files and parses each with
  tinycss2.  Reports parse errors at the tokeniser level (malformed tokens,
  unexpected characters) and declaration-level errors (missing ':' separator,
  empty value lists).  Accepts modern CSS (custom properties, var(), clamp(),
  vendor prefixes) without false positives.

check-embedded-js (scripts/check_js.py + py-mini-racer==0.6.0)
  Extracts every inline <script> block (skipping src= external scripts) and
  passes each through V8's Function constructor via py-mini-racer.  This
  catches all ES2020+ syntax errors (including optional chaining, async/await,
  nullish coalescing) without executing the code.

Supporting changes:
  • esc() refactored from 5 sequential .replace() calls to a single-pass
    lookup-table approach (avoids djlint misreading the bare />/g regex token;
    also slightly faster at runtime).
  • index.html reformatted by djlint --reformat (HTML structure only; CSS/JS
    content preserved verbatim).
  • tinycss2==1.5.1 and py-mini-racer==0.6.0 added to [project.optional-
    dependencies].development in pyproject.toml.

https://claude.ai/code/session_01LmU2X5jmgRZ1LHXc9S7bW1

Author: claude

.pre-commit-config.yaml

@@ -62,6 +62,23 @@ repos:
       entry: djlint --lint
       language: python
       files: \.(html|jinja|j2)$
+  -   id: djlint-check
+      name: HTML formatter check
+      entry: djlint --check
+      language: python
+      files: \.(html|jinja|j2)$
+  -   id: check-embedded-css
+      name: CSS linter (embedded styles)
+      entry: python scripts/check_css.py
+      language: python
+      files: \.(html|jinja|j2)$
+      additional_dependencies: [tinycss2==1.5.1]
+  -   id: check-embedded-js
+      name: JS syntax checker (embedded scripts)
+      entry: python scripts/check_js.py
+      language: python
+      files: \.(html|jinja|j2)$
+      additional_dependencies: [py-mini-racer==0.6.0]
   -   id: pydocstyle
       name: docstring style
       entry: pydocstyle --convention=google