fix(react): namespace SVG resource IDs per instance

[smbdy]

Summary

• namespace SVG clip path, gradient, mask, and fragment IDs per mounted React instance
• rewrite matching URL and href references in generated components and GitHub fallback SVGs
• avoid sharing cached converted fallback content when an SVG contains instance-bound IDs
• preserve the id-free generation and caching fast paths
• add a patch changeset for @bgd-labs/icons-react

Why

Multiple copies of the same icon previously emitted identical SVG resource IDs. Since fragment lookups are document-global, a copy in a hidden drawer or display-none subtree could capture the references from a visible copy and make that icon render blank.

Validation

• pnpm test: 216 tests passed
• pnpm typecheck
• pnpm lint
• pnpm format:check
• pnpm check:consumers: ESM, CJS, SSR, and tree-shaking passed
• pnpm size: all budgets passed
• publint and Are the Types Wrong passed for both packages
• production dependency audit: 0 vulnerabilities
• pnpm stress: 913 components, 1,748 code-split chunks, formula size budgets passed