chore: rename npm package to emberdb, switch to oidc trusted publishing

[kacy]

summary

• renames the npm package from ember-ts to emberdb (ember-ts was blocked by npm as too similar to ember-try)
• switches the npm publish job from NPM_TOKEN secret to OIDC trusted publishing — no token needed once the trusted publisher is configured in npm
• adds environment: npm to match the trusted publisher config

what was tested

• package manually published as emberdb@0.1.0 from local machine
• npm trusted publisher configured for kacy/ember, workflow release.yml, environment npm

setup required

create the npm environment in GitHub repo settings (Settings → Environments → New environment → name it npm). no protection rules needed.