feat: Added sectionate content processor.

TODOS.md

@@ -1,6 +1,7 @@
 - README.md
   - [ ] "Zero is beautiful"
 - [ ] Content-hash fingerprinting for CSS and JS cache busting
+- [ ] Enable configuration to  opt-out of features, particular pre/post processors.
 - [ ] proper date/time/now object.
 - [ ] Block attributes on code fences (`{ #ex-1 }`) — hello-world.md
 - [x] Emoji shortcodes (`:shrug:` etc.) — 2 instances
@@ -17,6 +18,10 @@
     guide
 - [ ] Search for grammars in multiple places
 - [ ] Download missing grammars.
+- [ ] Syntax highlighting in production: CI (`nix build` on ubuntu-latest) has no grammar `.so`s and a machine-specific `QUERIES_PATH` nix store hash, so the deployed site renders unhighlighted. Provide grammars + queries as nix build inputs and pass paths to thor at runtime (env vars/flags).
+- [ ] Durable highlight paths: read `GRAPHS_PATH`/`QUERIES_PATH` from env vars set by the flake instead of hardcoded nix store hashes, so they survive `nix flake update` and let the grammar/query version-mismatch detector fire automatically.
+- [ ] Unit tests for highlighting helpers: `capture_name_to_css`, `escape_html`, `unescape_html`, `extract_query_token`, `helix_version_from_path`.
+- [ ] Dark `<pre>` code-block background — atom-one-dark colors are tuned for a dark bg but currently render on the light `--color-body`. (See "Theme selector" item.)
 - [ ] Review every file in thor
   - [ ] Review alerts.odin
   - [ ] Review content.odin