V3 react support (#3)

* feat: v3 with React-friendly inputs and build-dir bug fix

Splits working-directory (source) from publish-dir (build output) so
React/Vite/CRA projects can run their build inside the source dir and
publish the artifact emitted next to it. Pipeline now chdirs before
build, so publish-dir resolves correctly relative to working-directory
and the prior './build/build' bug is gone.

Bumps runtime to node22 and rewrites README around the React story.

* docs: comprehensive v3 README rewrite with React/Vite focus

Rewrite README.md as a complete reference for v3, including:

- Table of contents
- 9 example sections covering Vite, CRA, ProCode/flat, pre-build
  checks, per-environment manifest overrides via `da apply-manifest`,
  multi-env deploys keyed off branch, path-filtered triggers,
  outputs/notifications (Slack + PR comment), and pnpm/yarn setup
- Inputs/outputs reference tables clarifying that `publish-dir` is
  resolved relative to `working-directory`
- "How it works" — explicit 6-step pipeline (detect → install →
  install ryuu → auth → build → publish) so users understand what
  the action does for them
- Callout that no separate `npm install` / `yarn install` /
  `pnpm install` step is needed — the action runs it
- CRA + `da apply-manifest` note: pin `@domoinc/da` as a
  devDependency to avoid `sh: 1: da: not found` in CI's clean install
- Manifest fields table including id/proxyId/collections semantics
- Migration-from-v2 diff explaining why publish-dir was added
- 6-row troubleshooting table covering manifest-not-found, auth,
  duplicate-app id, repo leak (the v2 working-directory trap), the
  da-not-found pattern, and AppDB proxyId

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* ci: bump runner Node to 22 to match package.json engines

The package declares engines.node >= 22.0.0 (matching action.yml's
runtime: node22), but both workflows were pinned to setup-node@20.
Yarn 1 enforces engines on install, so CI failed with:

  error domo-publish-action@3.0.0: The engine "node" is incompatible
  with this module. Expected version ">=22.0.0". Got "20.20.2"

Aligning CI to the same Node major the action runs on.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix: use node24 runtime (node22 not supported by GitHub Actions)

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jontiritilli

action.yml

@@ -27,5 +27,5 @@ outputs:
   app-url:
     description: "URL of the deployed app"
 runs:
-  using: "node22"
+  using: "node24"
   main: "dist/index.js"

package.json

@@ -34,7 +34,7 @@
     "prettier": "^3.6.2"
   },
   "engines": {
-    "node": ">=22.0.0"
+    "node": ">=20.0.0"
   },
   "lint-staged": {
     "src/**/*.js": [