docs: fix aztec-nr v4.2.0 documentation issues from audit

[critesjosh]

Summary

• Fix 52 issues across all aztec-nr doc pages identified during a manual review against nargo 1.0.0-beta.18 and local Aztec network v4.2.0-aztecnr-rc.2
• Fixes applied to both docs-developers/ (source) and developer_versioned_docs/version-v4.2.0-aztecnr-rc.2/ (versioned copy)
• Key categories: deprecated import paths, missing API parameters (capsule scope), non-existent methods (simulate_utility, msg_sender().unwrap()), incorrect struct names, out-of-bounds array access in code examples, wrong dependency URLs, stale content removal

Critical fixes (would cause compilation failures if copied from docs)

• Add missing scope parameter to all capsule API examples
• Fix CapsuleArray::at() call signature (2 args → 3)
• Fix out-of-bounds array access in sort_efficient example
• Update debug_log import path (dep::aztec::oracle::debug_log → aztec::oracle::logging)
• Replace simulate_utility() with execute_utility()
• Fix NoteMessagePendingDelivery → NoteMessage
• Correct partial note commitment structure (storage_slot in completion phase, not partial phase)

Other fixes

• Update all dep:: import prefixes to current unprefixed style
• Fix dependency URLs from aztec-packages repo to aztec-nr repo
• Correct ONCHAIN_CONSTRAINED link that pointed to ONCHAIN_UNCONSTRAINED
• Remove stale TODO comments, placeholder image, delegate_call references
• Update pedersen → poseidon2, return_values: BoundedVec → return_hash: Field
• Fix variable name mismatch (TWO_POW_32 → TWO_POW_16)
• Add missing unconstrained keyword to utility function examples
• Add missing #[derive] attributes on NFTNote in AIP-721

Test plan

• Verify docs build succeeds (yarn build in docs/)
• Spot-check code examples against source at v4.2.0-aztecnr-rc.2 tag
• Review rendered pages for formatting issues