Update all examples to Aztec v5.0.0-rc.1

[critesjosh]

Updates every example in the repo from Aztec v4.3.0 to v5.0.0-rc.1, migrating both Noir and TypeScript to the v5 APIs and following the aztec-kit conventions where relevant. All five examples build/run on v5 and are covered by CI.

Scope

Example	Noir	TS	CI
custom-note	✅ compiles	—	✅ new (compile)
note-send-proof	✅ circuits + uint-note + contract	✅ scripts + vite build	✅
prediction-market	✅ compiles + codegen	✅ typechecks	✅
recursive_verification	✅ circuit + contract compile	✅ typechecks; data.json regenerated	✅
test-wallet-webapp	—	✅ vite build	✅

Version bumps

• Nargo.toml git deps: tag = "v4.3.0" → v5.0.0-rc.1 (aztec-nr, uint-note, balance-set, bb_proof_verification)
• package.json @aztec/*: 4.3.0 → 5.0.0-rc.1; package names reconciled to actual imports (e.g. @aztec/constants, @aztec/entrypoints added where used)
• Docs/CI: aztec-up 5.0.0-rc.1; bundled nargo 1.0.0-beta.21 → 1.0.0-beta.22; CI AZTEC_VERSION: 5.0.0-rc.1

Key API migrations

Noir (Aztec.nr)

• MessageDelivery.X → MessageDelivery::x(); messages::message_delivery → messages::delivery
• context.push_nullifier → push_nullifier_unsafe
• uint-note local copy ported to v5 (npk_m_hash, compute_note_hash/compute_note_nullifier, DOM_SEP__PARTIAL_NOTE_COMMITMENT)

TypeScript (Aztec.js)

• Prefunded test accounts are now initializerless: createSchnorrAccount → createSchnorrInitializerlessAccount
• DeployMethod address-affecting options moved to construction-time bag; .send() returns { contract, receipt, instance }
• Gas: estimatedGas result → gasUsed via { includeMetadata: true }
• recursive_verification: data.json regenerated (UltraHonk proof 500 → 458 fields)

Removed: account-contract example

The repo previously had a custom password-based account contract example. While migrating it I found it can't be exercised on v5 with the standard tooling: the EmbeddedWallet resolves a tx's from to a built-in schnorr/ecdsa account by type and offers no hook to register a custom account, so the example could only ever deploy — never actually authorize/send a tx through its entrypoint. (This isn't specific to the password design — it applies to any custom account type, and the aztec-kit reference only ever sends from schnorr/ecdsa accounts.) Rather than ship a deploy-only example that misleads — or maintain fragile low-level PXE plumbing — the example was removed along with its CI workflow and doc references.

CI coverage

Added custom-note-tests.yml (contract-only compile) so the one remaining example that lacked CI is now covered. All five examples are in CI.

Docs / tooling cleanup

• Root README.md + CLAUDE.md: removed the stale starter-token references; documented all current examples; corrected the project structure, CI list, and dependency snippet.
• Replaced dead aztec start --sandbox with aztec start --local-network (the --sandbox flag no longer exists in v5) across READMEs and helper scripts.
• Standardized on yarn (the repo convention): converted the lone bun-based prediction-market CI/scripts to yarn (adding the --experimental-vm-modules flag its jest setup requires, matching note-send-proof); fixed bun/npm drift in recursive_verification/note-send-proof docs and scripts; refreshed the stale recursive_verification/debug.sh.
• Removed the empty placeholder folders offchain-account-ownership/ and streaming-payments/ (each held only a .gitignore) and gitignored the .playwright-mcp/ tool-artifact dir.

Verification

Every Noir contract/circuit compiles under the installed 5.0.0-rc.1 toolchain and all TypeScript typechecks/builds. The integration-test workflows run against a live local network. All five CI workflows are green on the latest commit.