Snconsistent environment setup and missing version constraints causing example failures

[endovix]

While working with the repository, I noticed that several examples fail depending on the local environment configuration (Node.js, Solana CLI, Anchor, etc.).

There are existing issues related to build/test failures (e.g. Node.js version incompatibility), which suggests that the repository currently lacks strict version control or reproducible setup.

Problems observed:
-No .nvmrc, .tool-versions, or Docker setup for consistent environments
-Node.js version incompatibilities (e.g. Node 23 issues)
-Anchor / Solana CLI version mismatches are not documented
-Examples rely on pnpm but version is not enforced
-Some tests fail depending on local setup

Expected behavior:
All examples should run consistently across environments with minimal setup.

Similar issues have already been reported regarding build failures, indicating this is a recurring problem rather than an isolated case.

[mansiverma897993]

@endovix can you assign this issue to me ? or i can raise PR directly ?

[dev-jodee]

Fixed by #656 (b0d0c181): .nvmrc + rust-toolchain.toml at the root, anchor/solana versions pinned in every Anchor.toml, lockfiles enforced in CI, one test harness everywhere. .tool-versions lands with #605. If something still breaks on a clean machine, open a new issue naming the example.