feat(cli): add browser Fetch and shared Redoc assets

[npalladium]

Summary

• expose httpsnippet's browser javascript_fetch target through the CLI
• add --redoc-bundle-url so split HTML docs can share one self-hosted Redoc bundle
• declare the Git-package preparation policy: allow esbuild's required install script and deny core-js's optional postinstall
• document and test Fetch snippets, bundle URL escaping, and conflicting Redoc options

Verification

• mise exec node@22 -- /Users/n/Library/pnpm/pnpm verify
• installed the CLI from the pinned Git commit and packages/cli subdirectory in a fresh PNPM project, with its workspace core overridden to the same commit
• browser Fetch CLI generation test
• custom Redoc bundle URL core and CLI tests

Consumer

This enables query-service PR https://github.com/zenstack-we360/query-service/pull/587 to build a committed, multi-page consumer API documentation site with cURL, Python Requests, and browser Fetch examples while serving one local Redoc asset.