Remove demo, change pnpm to npm, support react 18 & 19

Author: snwolak

.github/workflows/ci.yml

@@ -14,14 +14,31 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: pnpm/action-setup@v4
+      - uses: actions/setup-node@v4
         with:
-          version: 10.30.3
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+      - run: npm run verify
+
+  react-compat:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        react-major: [18, 19]
+
+    steps:
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-node@v4
         with:
           node-version: 22
-          cache: pnpm
+          cache: npm
 
-      - run: pnpm install --frozen-lockfile
-      - run: pnpm verify
+      - run: npm ci
+      - run: npm install -w @protohiro/state-layers --no-save -D react@^${{ matrix.react-major }} react-dom@^${{ matrix.react-major }} @types/react@^${{ matrix.react-major }} @types/react-dom@^${{ matrix.react-major }}
+      - run: npm run -w @protohiro/state-layers typecheck
+      - run: npm run -w @protohiro/state-layers test
+      - run: npm run -w @protohiro/state-layers build

.github/workflows/release.yml

@@ -19,16 +19,13 @@ jobs:
       id-token: write
     steps:
       - uses: actions/checkout@v4
-      - uses: pnpm/action-setup@v4
-        with:
-          version: 10.30.3
       - uses: actions/setup-node@v4
         with:
           node-version: 20
-          cache: pnpm
+          cache: npm
           registry-url: 'https://registry.npmjs.org'
-      - run: pnpm install --no-frozen-lockfile
-      - run: pnpm build
+      - run: npm ci
+      - run: npm run build
       - name: Force npm auth file
         run: |
           echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" > ~/.npmrc
@@ -44,7 +41,7 @@ jobs:
       - name: Create release PR or publish
         uses: changesets/action@v1
         with:
-          publish: pnpm changeset publish
+          publish: npx changeset publish
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

AGENTS.md

@@ -108,7 +108,6 @@ Each state layer must verify:
 ## Repo Shape
 
 - `packages/react` publishes `@protohiro/state-layers`
-- `apps/demo` exists to prove the hooks on real elements, not to justify API experiments
 - shared runtime logic should stay small and live in the React package until duplication demands otherwise
 
 ## Current Foundation Expectations

Dockerfile.demo

@@ -2,6 +2,8 @@
 
 Protohiro State Layers is a small React library for visual state layers on existing elements. It focuses on the narrow problem of rendering states like focus, invalid, and loading without wrapper components or runtime geometry work.
 
+Supported React versions: `18.x` and `19.x`.
+
 This library is for design systems and product surfaces that already have real elements, existing class names, forwarded refs, and their own business state. It is not a component kit, not a validation engine, and not another state-management abstraction.
 
 ## Principles
@@ -17,9 +19,6 @@ This library is for design systems and product surfaces that already have real e
 ## Workspace
 
 - [`packages/react`](./packages/react) publishes `@protohiro/state-layers`
-- [`apps/demo`](./apps/demo) is a Vite demo app
-
-Production demo URL: [libs.protohiro.com/state-layers](http://libs.protohiro.com/state-layers/)
 
 ## Included first-pass hooks
 
@@ -106,10 +105,9 @@ Notes:
 ## Development
 
 ```bash
-pnpm install
-pnpm test
-pnpm build
-pnpm dev
+npm install
+npm run test
+npm run build
 ```
 
 ## Tradeoffs in this first pass