chore: migrate tutorials to protocol v0.15

[Keinberger]

Overview

This PR migrates all of the Miden tutorials (rust-client, web-client, and the miden-bank example) from protocol v0.14 to v0.15. The rust-client and web-client tutorials target the released v0.15 SDKs; the miden-bank example targets the v0.15 protocol plus the in-flight next compiler (the sibling-call branch), so this is a draft until those land (see "Why this is a draft").

Motivation

v0.15 changed a lot across the stack: AccountStorageMode folded into AccountType, the FungibleFaucet builder + TokenPolicyManager, Felt::new becoming fallible, the fungible-asset vault-key layout, PartialNoteMetadata, the MAST wire format, and the cargo-miden #[component]/#[account]/#[note]/#[tx_script] redesign. Every tutorial needed source-verified updates, not just a version bump.

Changes

rust-client

• Bumped miden-client / sqlite-store / protocol to 0.15; migrated all 11 src/bin/*.rs (drop .storage_mode(), AccountType::Public, Felt::new_unchecked, the FungibleFaucet + TokenPolicyManager faucet, and so on). cargo build is green.
• docs/src/rust-client/*.md migrated; cargo test --doc passes the no_run blocks.
• MASM: note::build_recipient becomes note::compute_and_store_recipient.

web-client

• Bumped @miden-sdk/* to 0.15.2; migrated lib/* + lib/react/* (faucet type: 0, fresh recipient accounts, the getItem(...) StorageResult handling).
• All five browser tutorials verified live on testnet via Playwright; see Tests.

miden-bank example

• The four cargo-miden contracts migrated to the next compiler model (#[component_storage] + #[component] trait/impl, #[account]/#[note]/#[tx_script]); a new miden-project.toml + .cargo/config.toml per contract. get_balance is renamed to get_depositor_balance (it collided with the built-in ActiveAccount::get_balance the account wrapper generates), and the v0.15 fungible-asset key layout (where asset.key[2] now folds in a metadata byte) is handled through a shared balance_key helper.
• Integration crate migrated: the new cargo_miden::run signature, a .masp persist step (the FPI #[account] macro searches target/miden/<profile> while the compiler writes target/midenc/miden/...), a build_tx_script_from_package helper (tx-script packages are TransactionScript-kind, not Executable), and the now-required InitStorageData seeding of the initialized slot. All MockChain tests pass (deposit x3, init, withdraw).
• docs/src/miden-bank/* migrated to match the code.

shared docs

• miden_node_setup.md node tag v0.14.6 becomes v0.15.0.

Why this is a draft

1. Compiler dependency: the miden-bank contracts build on the unmerged next compiler branch (i697-acc-sibling-call-part2), pinned by git in the contract Cargo.tomls. This needs a tagged compiler release before merge, and it tracks the project-template migration in feat: migrate to next compiler SDK (protocol v0.15) project-template#51.
2. Live-network bin limitation: the miden-bank initialize/deposit bins compile but currently fail to deploy a fresh account on testnet under the part2 toolchain. submit_new_transaction aborts during local execution with an advice-map miss, because miden-client cannot supply a lazily-requested witness/foreign-account advice entry for a fresh, uncommitted account. The identical flow passes under miden-testing's MockChain, so it is an upstream miden-client/part2 gap, not a tutorial bug. I filed it at Deploying a part2-compiled #[account] component fails at local execution: "value for key … not present in the advice map" (submit_new_transaction, new account) rust-sdk#2289, and the docs flag it as a known limitation with the MockChain tests as the verification path.

Tests

• web-client: all five tutorials (First rust-client example #1 create/mint/consume, First miden client tutorial  #2 multi-send with delegated proving, Initializing the repository and adding the first series of tutorials #3 increment counter, Tutorial for setting up the miden node locally #4 unauthenticated note transfer, feat: add node setup guide #5 foreign procedure invocation) run end-to-end in a real browser against testnet via Playwright, all passing, with a clean console (0 errors, 0 warnings across 127 log lines).
• miden-bank: cargo test is green on the part2 toolchain (deposit x3, init, withdraw via MockChain).
• rust-client: cargo build is green; cargo test --doc passes.

Open Questions

1. Compiler pin: the contract Cargo.tomls pin the next branch by git. Once there is a tagged compiler release I will switch the pin. Happy to hold this PR behind feat: migrate to next compiler SDK (protocol v0.15) project-template#51 if you would rather align the template first.
2. miden-bank live bins: keep initialize/deposit in the repo with the documented limitation + the upstream issue link, or gate them behind a notice until Deploying a part2-compiled #[account] component fails at local execution: "value for key … not present in the advice map" (submit_new_transaction, new account) rust-sdk#2289 is resolved?