[Phase 1] Configure and test CI/CD pipeline (#96)

.github/workflows/docs-deploy.yml

@@ -0,0 +1,64 @@
+name: Deploy Docs
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'website/**'
+      - 'project/src/**'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install root dependencies
+        run: npm ci
+
+      - name: Build library
+        run: npm run build
+
+      - name: Copy bundle to website
+        run: cp dist/astrochart.js website/public/astrochart.js
+
+      - name: Install website dependencies
+        run: npm ci
+        working-directory: website
+
+      - name: Build Astro site
+        run: npm run build
+        working-directory: website
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: website/dist
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-22.04
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

docs/docs-deploy.md

@@ -0,0 +1,108 @@
+# Docs Deployment Guide
+
+This document explains how the AstroChart documentation site is built and deployed to GitHub Pages directly from this repository.
+
+The live site is served at **https://astrodraw.github.io/AstroChart/**.
+
+---
+
+## What the Workflow Does
+
+The workflow file is located at `.github/workflows/docs-deploy.yml`.
+
+It runs on every push to `main` that touches either `website/**` or `project/src/**`, and can also be triggered manually.
+
+The workflow has two jobs:
+
+### Job 1: `build`
+
+1. **Checkout** — checks out the `AstroChart` repository.
+2. **Set up Node.js 20** — installs Node using `actions/setup-node`.
+3. **Install root dependencies** — runs `npm ci` at the repo root.
+4. **Build library** — runs `npm run build` to produce `dist/astrochart.js` (webpack UMD bundle).
+5. **Copy bundle to website** — copies `dist/astrochart.js` → `website/public/astrochart.js` so the live demos can load it.
+6. **Install website dependencies** — runs `npm ci` inside `website/`.
+7. **Build Astro site** — runs `npm run build` inside `website/`, outputting the static site to `website/dist/`.
+8. **Upload Pages artifact** — uploads `website/dist/` as a GitHub Pages artifact using the official `actions/upload-pages-artifact` action.
+
+### Job 2: `deploy`
+
+1. **Deploy to GitHub Pages** — deploys the uploaded artifact using the official `actions/deploy-pages` action. Uses GitHub's OIDC token — no secrets or SSH keys needed.
+
+---
+
+## One-Time Setup (GitHub Pages source)
+
+This only needs to be done once per repository.
+
+1. Go to the repository **Settings → Pages**:  
+   `https://github.com/AstroDraw/AstroChart/settings/pages`
+2. Under **Source**, select **GitHub Actions** (not a branch).
+3. Click **Save**.
+
+That's it. The workflow handles everything else automatically.
+
+> **Note:** GitHub automatically creates a `github-pages` environment on the first successful deploy. You can see it under **Settings → Environments**.
+
+---
+
+## How to Manually Trigger the Workflow
+
+You can trigger a deploy at any time without pushing code:
+
+1. Go to the **Actions** tab in the AstroChart repository:  
+   `https://github.com/AstroDraw/AstroChart/actions/workflows/docs-deploy.yml`
+2. Click **Run workflow**
+3. Select the branch (typically `main`)
+4. Click **Run workflow**
+
+The workflow will run and deploy the current state of `main` to GitHub Pages.
+
+---
+
+## How to Debug Deploy Failures
+
+### Step 1 — Check the workflow logs
+
+Go to `https://github.com/AstroDraw/AstroChart/actions` and click the failed run. Each step's output is expandable. Common failure points:
+
+| Step | Likely cause |
+|---|---|
+| Build library | TypeScript compile error or missing dep — run `npm run build` locally |
+| Build Astro site | MDX/Astro error — run `cd website && npm run build` locally |
+| Upload Pages artifact | `website/dist/` is empty or missing — check the Astro build step above it |
+| Deploy to GitHub Pages | Pages source not set to "GitHub Actions" — see one-time setup above |
+
+### Step 2 — Permissions error on deploy
+
+If the deploy job fails with a permissions error:
+
+- Verify the repository **Settings → Pages → Source** is set to **GitHub Actions**, not a branch.
+- Verify the workflow has the correct top-level permissions (`pages: write`, `id-token: write`).
+- Check that the `deploy` job declares `environment: name: github-pages`.
+
+### Step 3 — Verify the deployed site
+
+After a successful run:
+
+1. Visit `https://astrodraw.github.io/AstroChart/` — homepage should load.
+2. Open browser DevTools → Network tab — no 404s for `/AstroChart/astrochart.js`.
+3. Click through the sidebar — navigation should work.
+4. Open the browser console — no JS errors.
+
+If the site shows stale content, GitHub Pages may have a CDN cache delay of up to 10 minutes after deployment.
+
+---
+
+## Astro base path configuration
+
+The `website/astro.config.mjs` file is configured with:
+
+```js
+site: 'https://astrodraw.github.io/AstroChart',
+base: '/AstroChart',
+```
+
+The `base` option tells Astro to prefix all internal links and asset URLs with `/AstroChart`, which is required for a project repository deployed to a sub-path.
+
+If the site is ever moved to the root URL (`https://astrodraw.github.io/`), remove the `base` option and update `site` accordingly.

website/astro.config.mjs

@@ -3,7 +3,8 @@ import starlight from '@astrojs/starlight'
 import sitemap from '@astrojs/sitemap'
 
 export default defineConfig({
-  site: 'https://astrodraw.github.io/',
+  site: 'https://astrodraw.github.io/AstroChart',
+  base: '/AstroChart',
   integrations: [
     starlight({
       title: 'AstroChart',