Update build scripts and enhance development workflow: Revise package.json to streamline build commands, replacing deprecated scripts with new chapter-specific build commands. Update CONTRIBUTING.md to clarify local development instructions and improve chapter sync processes. Enhance README.md with updated serving and build commands for better user guidance. Add new types for Bun in devDependencies and update the feed and sitemap to reflect recent content changes.

CONTRIBUTING.md

@@ -19,11 +19,11 @@ Thank you for helping grow free, open textbooks.
 | Add a **catalog subject banner** | [§ Catalog subject banner](#catalog-subject-banner) |
 | Add a **curriculum** filter (e.g. GCSE) | [§ New curriculum label](#add-a-curriculum-label) |
 
-**Browse the catalog locally:** `bun run build:js && zola serve` → [http://127.0.0.1:1111/catalog/](http://127.0.0.1:1111/catalog/)
+**Browse the catalog locally:** `bun run dev` → [http://127.0.0.1:1111/catalog/](http://127.0.0.1:1111/catalog/)
 
-**Search locally:** After `bun run build:js`, run `bun run index:search` once (or again after changing chapter HTML), then `zola serve`. Try [http://127.0.0.1:1111/search/](http://127.0.0.1:1111/search/) or press ⌘K / Ctrl+K.
+**Search locally:** Run `bun run build:chapter ...` or `bun run build:site` after content changes to refresh the index, then use `bun run dev`. Try [http://127.0.0.1:1111/search/](http://127.0.0.1:1111/search/) or press ⌘K / Ctrl+K.
 
-**Build modes:** `bun run build` is smart/incremental for local iteration; use `bun run build:full` for a deterministic full rebuild (CI/release checks).
+**Build modes:** use `bun run build:chapter` for targeted chapter builds and `bun run build:site` for full rebuilds.
 
 ---
 
@@ -37,7 +37,7 @@ content/{subject}/{slug}/       → everything for the live page (one folder)
 
 - **Catalog** (`/catalog/`) — list, map (`?view=tree`), and for Mathematics a Compare doc (`?view=compare`, HTML partial `themes/openfreebooks/templates/partials/math-curricula-compare.html`). Curriculum names (DSE, IB, …) appear only in the catalog — not inside chapter prose ([spec.md](spec.md)).
 - Every chapter needs a **`description`** in curriculum JSON (map clamps to three lines).
-- **`bun run sync:chapters`** (also run automatically by `bun run build:js`) merges `core.html` + `supplement.html` into `_index.md` for Zola. Edit the HTML files, not the merged body in `_index.md`.
+- Chapter sync (merging `core.html` + `supplement.html` into `_index.md`) runs automatically in build commands. Edit HTML sources, not merged `_index.md`.
 
 ### Map graph rules (summary)
 
@@ -130,15 +130,15 @@ strand = "Number & Algebra"
 ### 4. Build and check
 
 ```bash
-bun run build:js    # sync:chapters + Vite bundle
-zola serve
+bun run build:chapter math/your-chapter-slug
+bun run dev
 ```
 
 - `/catalog/?subject=math` — chapter appears and links correctly.
 - `/math/your-chapter-slug/` — page renders.
 - `bun run build` — full production build.
 
-New subjects with shared CSS/JS: add `content/{subject}/subject.scss` and/or `subject.ts`; `sync:chapters` wires them automatically. No per-chapter template branches.
+New subjects with shared CSS/JS: add `content/{subject}/subject.scss` and/or `subject.ts`; chapter sync during build wires them automatically. No per-chapter template branches.
 
 ---
 
@@ -163,7 +163,7 @@ Add edges in `data/{subject}-curriculum.json`:
 1. `data/catalog.json` — add the subject to `subjects`.
 2. Create `data/{id}-curriculum.json` (same schema as `math-curriculum.json`; `strands` + optional `graph.edges`).
 3. Add `content/{subject}/` when you have live chapters.
-4. Run `bun run build:js` (this syncs chapter content and auto-registers subject CSS/JS modules).
+4. Run `bun run build:chapter {subject}/*` (this syncs chapters, rebuilds relevant widgets, and updates global outputs).
 
 ### Subject scaffold (copyable)
 
@@ -210,7 +210,7 @@ cwebp -resize 1400 0 -q 82 your-banner.jpg -o static/catalog/banners/math.webp
 { "id": "math", "name": "Mathematics", "banner": "/catalog/banners/math.webp" }
 ```
 
-4. Check locally: `bun run build:js && zola serve` → `/catalog/?subject=math`
+4. Check locally: `bun run build:chapter math/* && bun run dev` → `/catalog/?subject=math`
 
 Omit `banner` for subjects that should stay unchanged (e.g. roadmap-only placeholders).
 
@@ -228,14 +228,13 @@ Omit `banner` for subjects that should stay unchanged (e.g. roadmap-only placeho
 
 ```bash
 bun install
-bun run sync:chapters  # after content/ chapter changes
-bun run build:js       # sync + Vite
-bun run dev            # incremental sync + watch + zola serve
-bun run dev:full       # force full sync before dev
-zola serve
+bun run dev
+bun run build:chapter math/measures-dispersion math/loci
+bun run build:chapter math/*
+bun run build:chapter   # auto-detect changed chapters, list, confirm
+bun run build:site
 bun test
 bun run build
-bun run build:full
 ```
 
 - Do **not** commit `themes/openfreebooks/static/` (Vite output).