chore(release): prepare v2.1.0

[JWThewes]

Prepare Collaborative AI-DLC v2.1.0 from the 41 PRs merged since v2.0.0, through #465. Update the root package and lockfile, date the changelog for September 14, 2026, and document workspace exports, managed tools and environments, credential inheritance, tracker delivery updates, and runtime and deployment fixes.

The changelog links every Added entry to its PR and explicitly documents tracker comments when final delivery PRs/MRs are created (#399). Explain why Jira now requires write:jira-work and reauthorization: Jira receives delivery comments, while GitHub and GitLab issues also close after all delivery requests merge. Include the latest managed catalog UX improvements (#437), dependency and CodeQL security fixes (#456), and AgentCore workflow-checkpoint permission fix (#465). The release branch incorporates the latest main and retains version 2.1.0.

Update the ongoing release checklist, installation examples, tracker documentation, and OAuth setup instructions.

Validation on the refreshed release branch with Node.js 24:

• npm run release:check -- 2.1.0 --final --tag-must-not-exist passes; the remote tag is absent.
• Backend: 2,839 tests pass across 159 files through the normal commit hook, using Gremlin Server and DynamoDB Local containers.
• Release tooling: all 54 tests pass, including simulated fresh installation, v1 adoption, upgrades, and recovery.
• Affected managed-tool/environment frontend tests: all 45 pass; frontend typecheck and production build pass.
• Root and frontend production audits both report zero vulnerabilities, clearing the previously reported dependency blocker.
• Documentation build, repository formatting, AWS SDK alignment, changed-file lint and secret scanning, and git diff --check pass. Existing non-AWS dependency alignment and frontend bundle-size warnings remain.
• Reviewed every merged PR since v2.0.0, verified all release-note PR references against merged history, and preserved earlier release entries.

Before publication, require GitHub CI to pass and complete disposable AWS fresh-install/update and feature smoke tests. No AWS deployment tests, release tag creation, release publication, or release workflow dispatch were performed in this update. After validation and merge, confirm the publication date and dispatch Publish Release from main with version 2.1.0.

[jeromevdl]

We should also mention that we now update the tracker when PR is created (to understand why we need new permissions for Jira) #399

Also reference the PRs in your "Added"

[jeromevdl]

just a small update on the changelog