feat: add groupByColumnsOnLeft to MCP dashboard table tile schema

[alex-fedotyev]

Summary

Follow-up to #2149. Drew added groupByColumnsOnLeft to the
external-API table chart config and to the conversion path in #2149,
but the MCP hyperdx_save_dashboard tool did not advertise the field
on its table-tile schema. As a result, MCP clients had no way to
discover or set the option, even though the underlying save / fetch
plumbing already supports it.

This change adds the field to mcpTableTileSchema.config and extends
the existing multi-tile MCP test to assert a table tile with
groupByColumnsOnLeft: true round-trips through hyperdx_save_dashboard.

Test plan

• yarn tsc --noEmit clean in packages/api
• yarn lint clean in packages/api
• Existing MCP dashboard suite passes; the should create a dashboard with multiple tile types row now also asserts groupByColumnsOnLeft on the table tile round-trips
• External API tests covering groupByColumnsOnLeft round-trip still pass (no change to that surface; verified locally)

[vercel]

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Project	Deployment	Actions	Updated (UTC)
hyperdx-oss	Ready	Preview, Comment	May 5, 2026 7:50pm

[changeset-bot]

🦋 Changeset detected

Latest commit: 3de9c9a

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@hyperdx/api	Patch
@hyperdx/app	Patch
@hyperdx/otel-collector	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

🔵 Tier 2 — Low Risk

Small, isolated change with no API route or data model modifications.

Why this tier:

• Standard feature/fix — introduces new logic or modifies core functionality

Review process: AI review + quick human skim (target: 5–15 min). Reviewer validates AI assessment and checks for domain-specific concerns.
SLA: Resolve within 4 business hours.

Stats

• Production files changed: 1
• Production lines changed: 7 (+ 8 in test files, excluded from tier calculation)
• Branch: alex/HDX-mcp-groupby-lhs
• Author: alex-fedotyev

To override this classification, remove the review/tier-2 label and apply a different review/tier-* label. Manual overrides are preserved on subsequent pushes.

[github-actions]

PR Review

✅ No critical issues found.

The change is minimal and correct — groupByColumnsOnLeft is already fully supported in the external API layer (zod.ts:266, external-api/v2/utils/dashboards.ts:244,426). This PR simply exposes the missing field on the MCP schema so MCP clients can discover and set it.

• Schema addition uses consistent style (z.boolean().optional().describe(...)) matching adjacent fields like asRatio
• Test guards with toBeDefined() before accessing tableTile.config, so failure is safe
• Changeset file included
• groupBy: 'SpanName' added alongside groupByColumnsOnLeft: true in the test input, which is semantically correct (the option only matters when there are group-by columns)

[github-actions]

E2E Test Results

✅ All tests passed • 157 passed • 3 skipped • 1199s

Status	Count
✅ Passed	157
❌ Failed	0
⚠️ Flaky	6
⏭️ Skipped	3

Tests ran across 4 shards in parallel.

View full report →

[alex-fedotyev]

Good catch. Added expect(tableTile).toBeDefined() in 3de9c9a.