docs(agents): add AGENTS.md, skills index, and Cursor rules pointer

[cs-raj]

Summary

Introduces a single entry point for humans and AI agents (AGENTS.md) with detailed guidance under skills/*/SKILL.md, a short index in skills/README.md, and an optional ``.cursor/rules/README.md` pointer so Cursor users land on the same docs as everyone else.

Upgrades @contentstack/delivery-sdk to ^5.1.2 and updates package-lock.json so the tree matches the Delivery SDK v5 line expected by nuxt-contentstack (no cacheOptions / persistence changes in this app).

Changes

• Add AGENTS.md: repo purpose, stack, commands, CI workflow references, and links to each skill.
• Add skills/README.md: quick links to each SKILL.md without duplicating the AGENTS skill table.
• Add skills: dev-workflow, framework, contentstack-nuxt, testing, code-review (YAML frontmatter on each SKILL.md).
• Add .cursor/rules/README.md: points to AGENTS.md only.
• package.json / package-lock.json: bump @contentstack/delivery-sdk to v5 range; lockfile refresh.

[github-actions]

🔒 Security Scan Results

ℹ️ Note: Only vulnerabilities with available fixes (upgrades or patches) are counted toward thresholds.

Check Type	Count (with fixes)	Without fixes	Threshold	Result
🔴 Critical Severity	0	0	10	✅ Passed
🟠 High Severity	0	0	25	✅ Passed
🟡 Medium Severity	0	0	0	✅ Passed
🔵 Low Severity	0	0	0	✅ Passed

⏱️ SLA Breach Summary

✅ No SLA breaches detected. All vulnerabilities are within acceptable time thresholds.

Severity	Breaches (with fixes)	Breaches (no fixes)	SLA Threshold (with/no fixes)	Status
🔴 Critical	0	0	15 / 30 days	✅ Passed
🟠 High	0	0	30 / 120 days	✅ Passed
🟡 Medium	0	0	90 / 365 days	✅ Passed
🔵 Low	0	0	180 / 365 days	✅ Passed

✅ BUILD PASSED - All security checks passed

[github-actions]

🔒 Security Scan Results

ℹ️ Note: Only vulnerabilities with available fixes (upgrades or patches) are counted toward thresholds.

Check Type	Count (with fixes)	Without fixes	Threshold	Result
🔴 Critical Severity	0	0	10	✅ Passed
🟠 High Severity	0	0	25	✅ Passed
🟡 Medium Severity	0	12	500	✅ Passed
🔵 Low Severity	0	0	1000	✅ Passed

⏱️ SLA Breach Summary

⚠️ Warning: The following vulnerabilities have exceeded their SLA thresholds (days since publication).

Severity	Breaches (with fixes)	Breaches (no fixes)	SLA Threshold (with/no fixes)	Status
🔴 Critical	0	0	15 / 30 days	✅ Passed
🟠 High	0	0	30 / 120 days	✅ Passed
🟡 Medium	0	11	90 / 365 days	⚠️ Warning
🔵 Low	0	0	180 / 365 days	✅ Passed

ℹ️ Vulnerabilities Without Available Fixes (Informational Only)

The following vulnerabilities were detected but do not have fixes available (no upgrade or patch). These are excluded from failure thresholds:

• Critical without fixes: 0
• High without fixes: 0
• Medium without fixes: 12
• Low without fixes: 0

⚠️ BUILD PASSED WITH WARNINGS - SLA breaches detected for issues without available fixes

Consider reviewing these vulnerabilities when fixes become available.