feat(drizzle-kit): support non-interactive generate conflicts

[enki]

Refs #5307

Summary

• add a shared migration-question model plus non-interactive conflict resolvers for generate
• support drizzle-kit generate --preflight and --answers <json|path> without creating the migration folder during preflight
• make generate --preflight machine-readable by keeping the JSON payload on stdout and routing incidental info logs to stderr
• expose matching API support via generate*Migration(..., { answers }) and preflight*Migration() helpers

Testing

• pnpm -C drizzle-orm build
• pnpm -C drizzle-kit exec tsc -p tsconfig.build.json --noEmit
• pnpm -C drizzle-kit exec vitest run tests/api-generate.test.ts tests/generate-questions.test.ts
• pnpm -C drizzle-kit exec vitest run tests/cli-generate.test.ts tests/cli-preflight-output.test.ts
• pnpm -C drizzle-kit exec vitest run tests/pg-tables.test.ts tests/pg-columns.test.ts tests/rls/pg-policy.test.ts

[enki]

Follow-up commit pushed: preflight generate is now machine-readable on stdout, with config/schema info logs routed to stderr.