Align Terminus docs and NestJS migration guidance with shipped behavior

[ayden94]

Context

All 182 evidence anchors were verified. Node engine mismatch and dependency-only major intent were excluded as covered by open issue #3169 (#3169).

Audit Purposes

Docs-book sync and NestJS migration gap review.

Findings or R&D Brief

docs-sync#1: /ready is incorrectly documented with /health fields. Evidence: apps/docs/content/docs/guides/operations.mdx:155, apps/docs/content/docs/guides/operations.ko.mdx:155, packages/terminus/src/module.ts:247, packages/terminus/src/module.ts:291. docs-sync#2: the book attributes unsupported global shutdown control-plane behavior to Terminus. Evidence: book/beginner/ch18-health.md:244, book/beginner/ch18-health.ko.md:245, packages/terminus/src/module.ts:234, packages/terminus/src/module.ts:301. nestjs-migration#2: migration guidance must explain guard and decorator metadata boundaries. Evidence: docs/getting-started/migrate-from-nestjs.md:36, docs/getting-started/migrate-from-nestjs.ko.md:36, book/beginner/ch18-health.md:96, book/beginner/ch18-health.md:99, book/beginner/ch18-health.ko.md:96, book/beginner/ch18-health.ko.md:99, packages/terminus/src/types.ts:52, packages/terminus/src/types.ts:57, packages/runtime/src/health/health.ts:73, packages/runtime/src/health/health.ts:90. nestjs-migration#3: the multi-dependency example discards individual results. Evidence: book/beginner/ch18-health.md:114, book/beginner/ch18-health.md:115, book/beginner/ch18-health.md:116, book/beginner/ch18-health.md:120, book/beginner/ch18-health.ko.md:114, book/beginner/ch18-health.ko.md:115, book/beginner/ch18-health.ko.md:116, book/beginner/ch18-health.ko.md:120, packages/terminus/src/health-check.ts:327, packages/terminus/src/health-check.ts:346, packages/terminus/src/module.ts:240, packages/terminus/src/module.ts:249. nestjs-migration#4: the built-in/custom indicator migration map is incomplete. Evidence: packages/terminus/README.md:68, packages/terminus/README.md:74, packages/terminus/README.ko.md:68, packages/terminus/README.ko.md:74, docs/getting-started/migrate-from-nestjs.md:37, docs/getting-started/migrate-from-nestjs.ko.md:37, packages/terminus/src/indicators/index.ts:1, packages/terminus/src/indicators/index.ts:5, packages/terminus/src/redis.ts:1, packages/terminus/src/types.ts:17, packages/terminus/src/types.ts:21.

Contract Impact

Documentation and migration alignment only; no one-to-one NestJS parity claim.

Suggested Resolution

Correct response shapes and unsupported capability claims, explain guard boundaries, rewrite the example to retain every dependency result, and complete the built-in/custom indicator migration map.

Affected Packages

terminus.

Affected Surfaces

Website docs, book, package README, migration guide, and examples.

Why Now

Current guidance can hide dependency results and mislead migrations about routes, guards, and indicator ownership.

Acceptance Criteria

• EN and KO docs distinguish /health and /ready.
• Unsupported global shutdown claims are removed.
• Guard and metadata boundaries are explicit.
• The example preserves all four individual dependency results.
• Built-in/custom indicator migration paths and subpath ownership are complete in EN and KO.