[stepashka]

Summary

• Generate a withLakebaseTraceContext helper for direct Lakebase SQL in AppKit scaffolds. It reads the active OpenTelemetry span at query execution, adds a W3C traceparent comment and sanitized service label, and preserves query parameters and sampling flags. Queries without a valid active span remain unchanged.
• Use the helper in the sample Lakebase routes and document app span export and captured plan correlation. The helper covers these direct string queries; raw pools, checked-out clients, ORMs, and the optional agent tool are outside this change.
• Sync the scaffold manifest and lockfiles. Correct existing Knip exclusions for the published CLI file and dependencies used by repository tools so the required commit and CI check passes.

Validation

• Node 22.23.4 and pnpm 11.0.8: pnpm build, pnpm docs:build, pnpm check:fix, pnpm -r typecheck, pnpm test (333 files and 6,174 tests passed; one skipped), pnpm check, pnpm docs:check, pnpm knip, license and template dependency checks, generated types and manifest sync, and public registry lockfile checks.
• Rendered scaffolds with Lakebase enabled and disabled. The enabled scaffold passed 13 tests with both pnpm and npm and built successfully. Both package manager template install/build/startup smoke checks passed.
• Ran two concurrent HTTP requests through the generated helper and a real Lakebase PostgreSQL branch. Both parameterized queries returned their values, and each SQL comment matched its exported request span. The service label was sanitized.
• The playground integration suite passed 29 tests with installed system Chrome. The standard local run could not launch because this machine lacks Playwright's pinned Chromium binary; CI installs that binary.

Remaining verification

I could not read system.lakebase.plan_history from the available test workspace because the principal lacks USE SCHEMA on system.lakebase. The live test above verifies SQL execution and span/comment identity, but a captured plan row remains unverified. This PR is a draft for that reason.

The downstream app-templates repository is populated by AppKit's release sync; I validated its rendered Lakebase variant locally and am leaving that update to the existing sync process.