feat(compression/cnft-burn): add pinocchio example

[MarkFeder]

Ports compression/cnft-burn to Pinocchio — the first Pinocchio example in compression/.

Program

A single instruction that CPIs into mpl-bubblegum's Burn, replacing a compressed NFT's leaf with an empty node. The burn arguments (root, data_hash, creator_hash, nonce, index) are already in bubblegum's wire order, so the CPI data is the discriminator followed by the instruction data verbatim — no borsh round-trip.

Two things differ from the Anchor variant:

• Variable-length account list. The merkle proof arrives as an account tail, so the CPI accounts are built into a fixed-size stack array and passed with invoke_with_bounds instead of the const-generic invoke. MAX_PROOF_ACCOUNTS is capped at 24, which keeps the list off the heap and covers any proof that fits in a transaction.
• CPI target is a constant. The bubblegum program is still taken as an account (it has to be in the transaction), but the CPI always targets the hardcoded program id. The tree authority is rederived on-chain and checked before the CPI.

Tests

The Anchor variant is in .ghaignore because its tests need devnet and a DAS indexer. This one runs entirely under LiteSVM against the mainnet-dumped bubblegum, account-compression and noop programs (prepare.mjs dumps them on postinstall, same pattern as nft-operations):

1. allocates a depth-3 tree and initializes it via create_tree
2. mints a cNFT with mint_v1
3. burns it through the Pinocchio program

Steps 1 and 2 recompute the expected root off-chain and assert it against the tree's own change log, so the leaf, data and creator hashes the burn depends on are verified independently rather than just "the transaction succeeded". Step 3 asserts the tree is empty again afterwards.

Verification

cargo build-sbf, isolated and workspace clippy -D warnings, cargo fmt --check --all, tsc --noEmit, prettier --check, and the 3-test LiteSVM suite all pass locally.

[greptile-apps]

Greptile Summary

The PR adds a Pinocchio compressed-NFT burn example that forwards Bubblegum burn arguments through CPI and verifies the flow with LiteSVM.

• Adds the on-chain burn handler, Bubblegum PDA validation, and bounded variable-length proof forwarding.
• Adds fixture preparation and end-to-end tests covering tree creation, minting, and burning.
• Registers the program in the Rust workspace and adds its JavaScript and Rust dependencies.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains; the previously reported persistent Solana CLI endpoint mutation is removed by applying the mainnet override only to each program-dump command.

Important Files Changed

Filename	Overview
compression/cnft-burn/pinocchio/prepare.mjs	Dumps each required mainnet program with a command-scoped cluster override, resolving the prior persistent CLI configuration mutation.
compression/cnft-burn/pinocchio/program/src/instructions/burn_cnft.rs	Implements the bounded Bubblegum burn CPI, validates instruction length and tree authority, and forwards proof accounts.
compression/cnft-burn/pinocchio/tests/test.ts	Exercises tree creation, compressed-NFT minting, root verification, and burning under LiteSVM.
compression/cnft-burn/pinocchio/package.json	Defines fixture preparation, build, deployment, and test scripts with dependencies resolved by the committed lockfile.
Cargo.toml	Adds the Pinocchio cNFT burn program to the Rust workspace.

_{Reviews (3): Last reviewed commit: "cnft-burn: raise the proof cap to the pr..." | Re-trigger Greptile}

[MarkFeder]

@amilz could you take a look at this one when you get a chance?

No open review threads left on it, so it is ready for maintainer review. It is one of 23 open Pinocchio ports I have up — they are independent and self-contained, so they can be reviewed and merged in any order: https://github.com/solana-developers/program-examples/pulls/MarkFeder