feat: add Figma investor and issuer product portal demo

[0xMuang]

Summary

• add a dependency-free 1440px investor and issuer product portal demo aligned with the Figma flows
• implement investor qualification, provider/file simulation, RFQ quote/fill and post-trade state
• implement issuer asset setup, rule selection, evidence modals, review, activation and metrics
• keep wallet, PII, provider, legal, signer and settlement authority outside this reference UI

Verification

• npm test --prefix services/product-portal-demo
• Chrome 1440x900 visual review for investor home, issuer rules and investor order
• Chrome CDP end-to-end interaction walkthrough (11 assertions)
• controlled full scripts/check.sh: Foundry 870/870, all service smoke, deploy-v3 10/10
• git diff --check

Notes

• direct current-tree scripts/check.sh still stops at the two pre-existing Solidity formatting differences; the full check temporarily formatted and restored those files under a trap
• no Anvil/GIWA E2E was rerun because this change adds a browser-only mock and does not touch contract, deployment, RPC or testnet paths
• existing untracked local files were not staged or modified

[0xMuang]

이 포털은 production main 기능이 아니라 발표용 데모로 유지하기로 결정했습니다. #92와 후속 #93을 모두 포함한 최종 상태는 demo/portal-v1 브랜치와 demo-portal-v1.0.0 태그에 보존했습니다. 따라서 main 병합 없이 이 PR을 닫습니다.