feat(screenshots): automated marketing/README screenshot pipeline

[enyineer]

What

Adds a private @checkstack/screenshots tooling package that regenerates the full README/marketing screenshot set reproducibly, and refreshes the README images to match.

The pipeline:

1. Spins up a throwaway Postgres (Testcontainers) and boots the real backend against it.
2. Seeds a believable demo world via the SDK/RPC: grouped systems, health checks across every strategy, SLOs, incidents, maintenance windows, a layered dependency graph, teams, satellites, GitOps secrets, a seeded AI chat transcript, and an in-app notification inbox.
3. Writes historic time-series (runs, aggregates, state transitions, SLO downtime/snapshots/streaks, anomaly baselines) directly into the owning plugins' tables so every chart, run list, and budget renders populated.
4. Drives headless Chromium to capture 34 dark-theme, retina screenshots of every major surface into a staging dir, then converts to WEBP.

Notes

• Checks are created disabled then flipped on in the DB post-seed, so registered strategies never fire a live probe against the fake hosts (which would crash the hermetic backend).
• Strategy ids are the registered namespaced ones (e.g. healthcheck-http.http) so the editor, run executor, and run-detail charts resolve them.
• No changeset: @checkstack/screenshots is private checkstack.type: "tooling"; the rest is docs/images only.
• Marketing site (separate repo) already updated to match.

🤖 Generated with Claude Code

https://claude.ai/code/session_01YMhaEJfwh7taURuBGRqo6C

[gitguardian]

⚠️ GitGuardian has uncovered 1 secret following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secret in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
34519086	Triggered	Company Email Password	843d71e	core/screenshots/src/config.ts	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
2. Replace and store your secret safely. Learn here the best practices.
3. Revoke and rotate this secret.
4. If possible, rewrite git history. Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data.

To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

---

^{🦉 GitGuardian detects secrets in your source code to help developers and security teams secure the modern development process. You are seeing this because you or someone else with access to this repository has authorized GitGuardian to scan your pull request.}

[changeset-bot]

⚠️ No Changeset found

Latest commit: 843d71e

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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

[github-actions]

✅ All PR Checks Passed

Check	Status
Typecheck	✅ Passed
Lint	✅ Passed
Deps	✅ Passed
Test	✅ Passed
Integration	✅ Passed
Security	✅ Passed
E2E	✅ Passed

@enyineer All quality checks have passed. This PR is ready for your review.