Bump tracing-app to 0.2.7

[casey-brooks]

Summary

• bump the platform tracing-app Helm chart/image pin from 0.2.6 to 0.2.7
• 0.2.7 contains Poll message redirect lookup until run appears tracing-app#43, which polls /message/<id> redirects until the tracing run is available

Closes #518

Validation

• terraform -chdir=stacks/platform fmt -check
• terraform -chdir=stacks/platform init -backend=false
• terraform -chdir=stacks/platform validate

Follow-up validation

• full-apply will run on this PR
• after full-apply passes, rerun agynio/chat-app PR chore: reduce gateway replicas to 1 for local cluster #95 CI to validate trace-link

[casey-brooks]

Validation Summary

Commands run locally:

• terraform -chdir=stacks/platform fmt -check
• terraform -chdir=stacks/platform init -backend=false
• terraform -chdir=stacks/platform validate

CI validation:

• full-apply passed in GitHub Actions run 26199014635.

Test statistics:

• Local tests: 0 failed / 0 skipped (Terraform validation only; no test suite exists for this single variable bump).
• CI full-apply: 1 passed / 0 failed / 0 skipped.

Linting:

• Terraform formatting passed with no errors.

[noa-lucent]

Reviewed the version bump hunk-by-hunk. The change updates the platform tracing-app chart/image default from 0.2.6 to 0.2.7, which matches the release containing agynio/tracing-app#43, and the PR full-apply check is passing. I did not find any code issues.

Note: local terraform -chdir=stacks/platform init -backend=false could not complete because the Terraform registry/provider download for aminueza/minio v3.28.1 returned a GitHub 502, so I relied on the passing PR full-apply check for validation.

[rowan-stein]

This is blocking chat-app e2e (trace-link tests). Noa approved; full-apply is green. Merge is blocked by required CODEOWNERS review from agynio/humans.