add pinocchio escrow example

[MarkFeder]

What

Adds a Pinocchio implementation of tokens/escrow, alongside the existing anchor and native versions. This is the second Pinocchio token example (after transfer-tokens) and the first Pinocchio example to use a PDA-owned vault.

Scope

A faithful port of the native escrow with two instructions:

• MakeOffer — derives and creates the offer PDA ([b"offer", maker, id]), creates a vault associated token account owned by that PDA, transfers the maker's token A into the vault, and stores the offer terms.
• TakeOffer — the taker sends the maker the requested token B, the offer PDA signs to release the vaulted token A to the taker, then the vault and offer accounts are closed.

It's pure SPL (token + associated-token-account CPIs) — no Metaplex — using pinocchio-token, pinocchio-associated-token-account, pinocchio-system, and pinocchio-pubkey.

Notes

• Account orderings mirror tokens/escrow/native so the three options stay directly comparable.
• The one idiomatic-Pinocchio difference: the offer PDA bump is passed in the MakeOffer instruction data (and stored), so the program uses pinocchio_pubkey::derive_address instead of an on-chain find_program_address. TakeOffer reads the bump back from the stored offer.
• This adds pinocchio-token = "0.5.0" and pinocchio-associated-token-account = "0.3.0" to [workspace.dependencies] — the same two deps introduced by the transfer-tokens Pinocchio PR (add pinocchio transfer-tokens example #596). If that merges first, this rebases trivially (the lines are identical).
• The TS toolchain (package.json / pnpm-lock.yaml / tsconfig.json) is copied from tokens/escrow/native, so the lockfile is self-consistent and the bankrun test reuses the same setup helpers.

Tests

tests/test.ts runs under bankrun and mirrors the native escrow's assertions: it mints token A to the maker and token B to the taker, makes an offer (asserting the stored offer fields and the vault balance), then takes it (asserting both accounts are closed and the tokens landed correctly).

Locally green: cargo fmt --check, cargo clippy -- -D warnings, and biome check all pass on the new files.