feat: production grade Reactisma StyledComponent v2 and neural net improvemnts

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

.gitattributes

@@ -0,0 +1,11 @@
+* text=auto eol=lf
+
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.webp binary
+*.woff binary
+*.woff2 binary
+*.wasm binary

.github/pull_request_template.md

@@ -0,0 +1,35 @@
+<!--
+Thanks for the PR. Please fill in the sections below.
+Delete sections that don't apply.
+-->
+
+## What
+
+<!-- One-sentence summary of the change. -->
+
+## Why
+
+<!-- What problem does this solve? Link issues with "Closes #123". -->
+
+## How
+
+<!-- A short walkthrough of the approach. Call out non-obvious decisions. -->
+
+## Course module
+
+<!-- If this PR maps to a course module (M0..M15), reference it here. -->
+
+- Module: <!-- e.g. M3 / PR #4 -->
+
+## Checklist
+
+- [ ] `npm run typecheck` passes
+- [ ] `npm run lint` passes (no new warnings)
+- [ ] `npm run format:check` passes
+- [ ] `npm test` passes
+- [ ] PR description explains the **why**, not just the **what**
+- [ ] No `console.log`, dead code, or commented-out blocks left behind
+
+## Screenshots / recordings
+
+<!-- For UI changes, please include a before/after. -->

.github/workflows/ci.yml

@@ -0,0 +1,48 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  verify:
+    name: Lint / Typecheck / Build
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: ['20.19.x', '22.12.x']
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Format check
+        run: npm run format:check
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Typecheck
+        run: npm run typecheck
+
+      - name: Test
+        run: npm test
+
+      - name: Build
+        run: npm run build

.github/workflows/deploy-preview.yml

@@ -0,0 +1,38 @@
+name: Deploy Preview
+
+on:
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: deploy-preview-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  preview:
+    runs-on: ubuntu-latest
+    name: Build for Vercel preview
+    if: ${{ secrets.VERCEL_TOKEN != '' }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22.12.x'
+          cache: 'npm'
+      - run: npm ci
+      - run: npm run typecheck
+      - run: npm run lint
+      - run: npm test
+      - run: npm run build
+      - name: Deploy to Vercel (preview)
+        run: |
+          npm i -g vercel@latest
+          vercel pull --yes --environment=preview --token=${{ secrets.VERCEL_TOKEN }}
+          vercel build --token=${{ secrets.VERCEL_TOKEN }}
+          URL=$(vercel deploy --prebuilt --token=${{ secrets.VERCEL_TOKEN }})
+          echo "Preview URL: $URL"
+          gh pr comment ${{ github.event.pull_request.number }} --body "Preview deploy: $URL"
+        env:
+          GH_TOKEN: ${{ github.token }}

.gitignore

@@ -22,3 +22,12 @@ dist-ssr
 *.njsproj
 *.sln
 *.sw?
+
+# Crash dumps
+*.stackdump
+
+# Test coverage
+coverage
+
+# Build artifacts
+.vite

.prettierignore

@@ -0,0 +1,10 @@
+node_modules
+dist
+build
+coverage
+.vite
+*.min.js
+*.min.css
+package-lock.json
+pnpm-lock.yaml
+yarn.lock

.prettierrc

@@ -0,0 +1,9 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "tabWidth": 2,
+  "printWidth": 100,
+  "arrowParens": "always",
+  "endOfLine": "lf"
+}

CONTRIBUTING.md

@@ -0,0 +1,78 @@
+# Contributing to Reactisma
+
+Thanks for considering a contribution. Reactisma is the companion repo of the Reactisma course, so a few conventions matter more here than in a typical OSS project:
+
+1. Every change should be educational. If a refactor is "just" cleaner, write a paragraph in the PR explaining the **why**.
+2. PRs map 1:1 with course modules where possible. If your change overlaps a planned module, please coordinate first (open an issue).
+3. We prefer **boring, readable code**. No clever one-liners that future course readers will trip over.
+
+---
+
+## Workflow
+
+1. Fork the repo and clone your fork.
+2. Create a branch off `main`: `git checkout -b feat/short-description`.
+3. Make changes, run `npm run typecheck`, `npm run lint`, `npm test`.
+4. Commit using **conventional commits** (see below).
+5. Push and open a PR against `main`. Fill out the template.
+
+---
+
+## Conventional commits
+
+Format: `<type>(<scope>): <summary>`
+
+Types we use:
+
+| Type | When to use |
+| --- | --- |
+| `feat` | A new feature or capability |
+| `fix` | A bug fix |
+| `perf` | A performance improvement |
+| `refactor` | Code change that neither fixes a bug nor adds a feature |
+| `docs` | Documentation only |
+| `test` | Adding/updating tests |
+| `chore` | Tooling, build, dependencies |
+| `style` | Formatting only (no logic change) |
+
+Scopes are loose but try to be one of: `vdom`, `hooks`, `scheduler`, `reconciler`, `dom`, `styled`, `nn`, `memory`, `ssr`, `worker`, `wasm`, `devtools`, `course`.
+
+Examples:
+
+```
+feat(hooks): add useReducer with action discrimination via TS narrowing
+fix(reconciler): preserve component instance when reordering keyed children
+perf(nn): switch dual hemispheres to Float32Array layout
+docs(course): expand module 4 outline with diagram links
+```
+
+---
+
+## PR checklist
+
+Before requesting review, please confirm:
+
+- [ ] `npm run typecheck` passes
+- [ ] `npm run lint` passes (no new warnings either)
+- [ ] `npm run format:check` passes
+- [ ] `npm test` passes
+- [ ] The PR has a description explaining **why** (not just what)
+- [ ] If the change is part of a course module, the module is referenced
+- [ ] No leftover `console.log`, commented-out code, or dead imports
+
+---
+
+## Code style
+
+- TypeScript strict mode is non-negotiable. Don't widen types with `any`; use `unknown` + narrowing.
+- Functions should fit on a screen. If they don't, split them.
+- Prefer pure functions in `utils/`. Side effects belong in components or in clearly-named lifecycle hooks.
+- Hooks must follow the rules of hooks. We will land a custom ESLint rule for this in M3.
+
+## Reporting issues
+
+Open an issue with a reproduction case (link to a fork, a CodeSandbox, or a minimal `.tsx` snippet) and the expected vs. actual behavior. Tag with `bug`, `enhancement`, `question`, or `course`.
+
+## License
+
+By contributing, you agree that your contributions will be licensed under the MIT License.