update: added skill files

[cs-raj]

DX-5359 — Contributor & agent documentation

Summary

Adds a single entry point and structured skills so humans and AI agents can navigate SDK conventions without duplicating Cursor-only rules. Short SKILL.md files link to exhaustive content under skills/*/references/.

What’s included (documentation)

• AGENTS.md — Repo purpose, stack, commands, CI pointers, and an index of all skills.
• skills/README.md — “When to use which skill” table; notes that deep content lives in references/.
• skills/<area>/SKILL.md — Lean entries for:
  • dev-workflow
  • sdk-core-patterns (+ references/sdk-architecture.md, references/aspnetcore-integration.md)
  • query-building (+ references/query-patterns.md)
  • models-and-serialization (+ references/serialization-patterns.md)
  • error-handling (+ references/error-patterns.md)
  • testing (+ references/testing-patterns.md)
  • code-review (+ references/code-review-checklist.md, references/red-flags.md)
• .cursor/rules/README.md — Points to AGENTS.md (no duplicate rule prose).
• README.md — One line linking contributors to AGENTS.md.

How to review

• Skim AGENTS.md → skills/README.md → any SKILL.md → follow references/ links for depth.
• Confirm internal markdown links resolve from each SKILL.md to its references/*.md files.

[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

[sunil-lakshman]

LGTM

[reeshika-h]

@cs-raj pls follow structure. The skill file should contain all details.

[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