feat(web): minimal explorer UI for the muzix protocol

[abhicris]

Summary

A minimal, mono-forward explorer UI for muzix at web/. Next.js 15 App Router + Tailwind, fully static, ~106 kB first-load JS. Ships with 6 mock catalog tokens so it works pre-deployment.

Routes

• / — hero, four-stat strip (catalog tokens · streams · revenue · MUSD), four-pillar grid, recent issuances
• /catalog — all tokens, each row has split-bar + provenance flag + ISRC waveform
• /catalog/[tokenId] — per-track detail: cap-table visualization, AI-provenance card (humanOnly attestation OR ERC-721-AI model bindings + lineage URIs), on-chain reference list
• /about — architecture (MuzixCatalog · MUSD · MuzixAIProvenance · StreamingRevenueOracle)
• /_not-found — 404 keyed to the catalog story ("Off-chain.")

Aesthetic

• Background #0a0a0a, text #f5f1e8, single accent #f5c451 (honey).
• Inter for prose, JetBrains Mono for ISRC / addresses / hashes.
• Pseudo-waveforms are deterministic per ISRC — same seed, same bars (no flicker, no client JS).
• All pages prerender as static HTML.

How it composes with the protocol

Mock data shape mirrors @kcolbchain/muzix-sdk types (MusicMetadata, RoyaltySplit, AIProvenance). Going live is:

1. Deploy MuzixCatalog, MUSD, MuzixAIProvenance, oracle to a public network.
2. Replace lib/mock-data.ts consumers with createMuzixClient({ contracts, transport }).catalog.read* etc.
3. Set NEXT_PUBLIC_RPC_URL + contract addresses via env.
4. Drop a Vercel project at muzix.kcolbchain.com.

No SDK runtime is wired in this PR — keeping the surface tight until contracts deploy.

Mock catalog covers the cases

Token	Style	Cap table	Provenance
#1 Lavender Cassette	indie band	4 recipients	human-only
#2 Aerie / Null	AI-stem mix	4 recipients incl. AI model owner	AI-attributed (1 model)
#3 Kōri Sato	solo	3 recipients	human-only
#4 Mira Volk	co-write	4 recipients	human-only
#5 Helios Ground	feat. AGI	5 recipients incl. 2 AI model owners	AI-attributed (2 models)
#6 Étoile du Soir	minimal	2 recipients	human-only

Test plan

• npm install clean
• npm run typecheck clean
• npm run build clean — 12 static pages prerendered
• All routes 200; unknown token → 404
• Verified hero, catalog list, AI-attributed detail, human-only detail, about, 404 all render with expected content
• Reviewer: pull and npm run dev to eyeball the aesthetic
• Reviewer: confirm path (web/) is fine, or rename to app/ later if monorepo conventions shift

Follow-ups (not in this PR)

• Wire @kcolbchain/muzix-sdk for live reads once contracts deploy.
• npm workspace at repo root linking sdk/typescript and web/ so the SDK can be consumed without a file: reference.
• Wallet connect (mint flow / claim flow) — gated on contract deployment.
• Vercel project at muzix.kcolbchain.com.