feat(ci): proactive deprecation and warning triage across build pipeline

[scottschreckengaust]

Problem

Build, test, lint, and synth steps emit deprecation warnings and non-fatal diagnostics that go unnoticed until they become breaking changes. By the time they break, the upgrade path is harder (multiple breaking changes compound). Examples from //cdk:test:

1. ts-jest hybrid module warning

WARN ts-jest[config] (WARN) message TS151002: Using hybrid module kind (Node16/18/Next) is only
supported in "isolatedModules: true". Please set "isolatedModules: true" in your tsconfig.json.

Risk: ts-jest may enforce this in a future major version, breaking all tests.

2. CDK deprecated API usage

WARNING [WARNING] aws-cdk-lib.aws_iam.GrantOnPrincipalOptions#scope is deprecated.

Risk: Removed in a future aws-cdk-lib major version. Every CDK upgrade will surface more of these until addressed.

Other known warnings (from CI logs)

• ESLint @cdklabs rules using removed context.getFilename() (chore(eslint): re-enable @cdklabs rules after plugin fixes deprecated context.getFilename() #170)
• ESLint no-constant-condition deprecated in ESLint 10 (already handled in feat(tooling): upgrade ESLint 9 → 10 with flat config migration #171)

Proposal

Establish a recurring process (manual or automated) that:

1. Captures — Collects all WARN/WARNING/deprecated output from mise run build
2. Triages — Categorizes by severity (breaking-soon vs cosmetic) and ownership
3. Tracks — Files issues for each actionable deprecation before it becomes a blocker
4. Prevents regression — Optionally, CI fails on NEW warnings (warnings-as-errors for net-new)

Implementation options (progressive)

Approach	Effort	Coverage
Periodic manual audit (run build, grep warnings, file issues)	Low	Reactive
CI step that captures warnings to artifact for review	Medium	Passive visibility
CI step that fails on net-new warnings (baseline file of known warnings)	High	Preventive

Relation to ADR-013 (proposed)

This aligns with ADR-013's Tier 1 (package-level build gates). A "no new warnings" policy would be a Tier 1 enforcement mechanism.

Immediate action items

• Fix ts-jest isolatedModules warning (cdk/tsconfig.dev.json)
• Triage GrantOnPrincipalOptions#scope deprecation (update CDK code to use non-deprecated API)
• Add to Remediate CDK Warnings #89 or close Remediate CDK Warnings #89 if subsumed here

References

• Remediate CDK Warnings #89 — Remediate CDK Warnings (narrower scope: CDK-nag + context flags only)
• RFC: Automated toolchain version monitoring and upgrade workflow #104 — Automated toolchain version monitoring (dependency versions, not build warnings)
• chore(eslint): re-enable @cdklabs rules after plugin fixes deprecated context.getFilename() #170 — @cdklabs ESLint plugin deprecation
• ADR-013 (proposed) — Tiered validation pyramid