docs: refresh Checkly CLI 8.19.0 skills

[vince-winkintel]

Upstream

• Checkly CLI: 8.19.0
• Release: https://github.com/checkly/checkly-cli/releases/tag/8.19.0
• Compare: checkly/checkly-cli@8.18.0...8.19.0
• Implementation: feat(constructs): derive response time limits from account features checkly/checkly-cli#1425

Upstream CLI changes

• Authenticated CLI commands now pass client-visible account feature flags into construct validation.
• Accounts with extended response-time limits skip fixed client-side ceilings and defer the actual upper bound to the Checkly API.
• Standard ceilings remain for accounts without that entitlement and for older/self-hosted APIs without feature flags.
• The degradedResponseTime <= maxResponseTime consistency check remains in force.
• The change covers API checks plus TCP, DNS, URL, gRPC, SSL, and traceroute monitors.
• Top-level command help is unchanged apart from the version string.

Skill/package changes

• Bump the skill-pack version from 1.0.11 to 1.0.12 in VERSION.
• Document account-aware API-check response-time validation in checkly-checks.
• Add standard per-monitor ceilings and account-entitlement behavior to checkly-monitors.
• Distinguish top-level degraded/maximum thresholds from request-level response-time assertions.
• Keep upstream CLI version history in VERSION; no version prose was added to SKILL.md files.

Validation

• npx --yes checkly@8.19.0 --version → checkly/8.19.0 darwin-arm64 node-v26.5.0
• Compared checkly@8.18.0 --help with checkly@8.19.0 --help; only the version line changed.
• Checked the tagged upstream construct source for all documented standard ceilings and extended-limit behavior.
• Skill sanity validator → PASS: 14 skill files; frontmatter names, descriptions, and code fences valid; VERSION=1.0.12; no CLI 8.19.0 prose in SKILL.md
• npx --yes skills@latest add . --list → local path valid; 14 skills discovered.
• bash -n scripts/*.sh → PASS: shell syntax for 4 scripts
• git diff --check → passed.

The repository has no package-level build harness. scripts/validate-config.sh validates a downstream Checkly project, so it was syntax-checked but not run in this skill-pack repository, which has no checkly.config.ts.

Vince, please review this refresh before merge.

[vince-winkintel]

Vince:Approved