feat(generate-blueprint): add TypeScript blueprint generation support

[chengyixu]

Summary

Adds a --ts CLI option to the generate-blueprint generator that produces TypeScript (.ts) blueprints instead of JavaScript (.js/.mjs).

Changes

• New ts config option (--ts CLI flag) to opt into TypeScript blueprint generation
• When ts=true, blueprintMjsExtension resolves to 'ts' instead of 'js'/'mjs'
• Generator files (index.ts, command.ts, generator.ts, generator.spec.ts) use .ts extensions with proper TypeScript type annotations (replacing JSDoc @type comments)
• .blueprint/ internal files (commands.ts, generator.ts, index.ts, etc.) also output as .ts with TypeScript syntax
• tsconfig.json template updated with TypeScript-optimized settings when ts is enabled:
  • module: "preserve" for native TS execution
  • noEmit: true
  • rewriteRelativeImportExtensions: true
  • erasableSyntaxOnly: true
  • verbatimModuleSyntax: true
• package.json additions for TypeScript mode:
  • typescript added as a devDependency
  • tsc added to the pretest script
  • Published files pattern updated to include .ts and exclude .spec.ts
• typescriptEslint enabled when ts mode is active
• 100% backward compatible - existing JS/MJS generation is completely unchanged

Design Decisions

• Follows the same patterns established in @mshima's entity-audit TypeScript branch
• Reuses the existing blueprintMjsExtension property (extending it to support 'ts' value) rather than creating a parallel system
• The ts option automatically sets js: false in the configuring phase
• Template EJS files conditionally output TypeScript syntax vs JSDoc based on blueprintMjsExtension === 'ts'

Closes #32217

Test plan

• Verify tsc --noEmit passes (confirmed locally)
• Run generate-blueprint with --ts flag and verify .ts files are generated
• Run generate-blueprint without --ts and verify existing behavior unchanged
• Run generate-blueprint --ts --local-blueprint and verify .mjs behavior for local blueprints
• Verify generated TypeScript blueprint can be installed and used with JHipster

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