[close - superseded by #24] docs: migrate recent changes from trunk-io/docs

[mintlify]

Summary

Migrates the two commits landed on trunk-io/docs main after the initial import (2026-05-14).

Changes

• index.mdx — apply welcome-copy update from (Chore): Fix copy on welcome page docs#663: rewrites the Trunk Flaky Tests paragraph to drop the stack-trace-embedding quarantine framing.
• flaky-tests/detection/index.mdx, failure-count-monitor.mdx, failure-rate-monitor.mdx, pass-on-retry-monitor.mdx, flaky-tests/management/test-labels.mdx — apply Document automatic label application from monitors docs#656: document the new monitor Action (Classify test status vs Apply labels), introduce the Dry-Running with Labels and Automatic labeling from monitors sections, and reshuffle related copy (resolution behavior, muting, detection type).

Links and code fences adjusted to docs2 conventions (.md → relative .mdx paths, {% hint %} → <Info>/<Warning>).

[samgutentag]

Verification status (2026-05-19): live

Verified: customers can use this. Ready to publish.

• Eng PRs: (Chore): Fix copy on welcome page docs#663 (welcome copy, merged 2026-05-14), Document automatic label application from monitors docs#656 (monitor framework, merged 2026-05-14)
• Flag: monitor action framework gated by showLabelActions (true in e2e default)
• Signals: same scope as PR [close - superseded by #24] docs: migrate recent updates from trunk-io/docs #23. Both [close - superseded by #24] docs: migrate recent changes from trunk-io/docs #13 and [close - superseded by #24] docs: migrate recent updates from trunk-io/docs #23 migrate the same two upstream PRs. PR docs(merge-queue): remove /trunk stack from stacked-pull-requests page #22 supersedes both with broader scope (includes Remove stacked PR references docs#657 stacked-PR rollback).

Note: superseded by PR #22. Consider closing.

[samgutentag]

Catchup check (2026-05-19): superseded by #24, recommend closing.

Compared this PR's tree against current main:

• All 6 files (index.mdx, flaky-tests/detection/{failure-count,failure-rate,index,pass-on-retry}-monitor.mdx, flaky-tests/management/test-labels.mdx) are byte-identical to main.
• Main already contains commit 1900ac5 from PR docs: migrate monitor label actions and welcome copy from trunk-io/docs #24 (merged 2026-05-18, "docs: migrate monitor label actions and welcome copy from trunk-io/docs"), which migrates the exact same upstream sources ((Chore): Fix copy on welcome page docs#663 + #656).
• A rebase here would produce an empty PR.

Recommend closing. PR #22 covers the one remaining upstream PR (trunk-io/docs#657: delete stacked-pull-requests page) that #24 did not.