fix: make Tevm examples release-ready

[roninjin10]

What changed

• pin Foundry 1.5.1 for MUD compatibility in CI and releases
• make the six top-level examples publishable under available @tevm/example-* names with public provenance metadata
• add release build, lint, typecheck, test, and docs gates
• make missing Vercel configuration fail visibly and target https://examples.tevm.sh
• update Vocs from 2.7.0 to the npm-latest 2.7.2 and improve extracted docs
• repair the missing Svelte Vite plugin, dead Optimism Goerli example, stale Next docs/key, and empty/dummy test coverage

Verified locally

Environment: Node 24.12.0, pnpm 9.15.9, Foundry 1.5.1.

• pnpm install --frozen-lockfile — passed from a clean install
• pnpm lint — passed (394 files; one Biome deprecation info)
• pnpm typecheck — passed
• pnpm build — passed for Bun, esbuild, MUD contracts/client, Next, SvelteKit, and Vite
• pnpm test — passed: Bun 1 passed/1 RPC test skipped; esbuild 1 passed/1 RPC test skipped; MUD Forge 2 passed; Next 3 passed; Svelte 1 passed; Vite 1 passed
• pnpm docs:build — passed; Vocs generated 35 files and a sitemap for examples.tevm.sh
• actionlint and git diff --check — passed
• pnpm changeset status — next public versions: Bun 0.0.2, esbuild 0.0.2, MUD 0.0.1, Next 0.0.2, Svelte Ethers 0.1.4, Vite 0.0.2
• npm view — all referenced Tevm versions exist; all six new package names currently return E404 and are available

Known external requirements

• @tevm/mud is still unpublished. The MUD browser client compiles via an optional peer plus temporary ambient declarations/externalization, but cannot load that package at runtime until it is published.
• The repository currently has no Actions secrets. Add NPM_TOKEN before merging a release PR.
• Add VERCEL_TOKEN, VERCEL_ORG_ID, and VERCEL_PROJECT_ID, and connect examples.tevm.sh; the domain currently returns Vercel DEPLOYMENT_NOT_FOUND.
• Bun and esbuild live fork tests remain skipped without RPC_URL / RPC_URL_MAINNET; offline smoke tests now always run.