fix(security): resolve IPv4 signed 32-bit integer overflow in SSRF pr…

[desireddymohithreddy0925]

Summary

Resolves a critical Server-Side Request Forgery (SSRF) bypass by fixing a signed 32-bit integer overflow in the IP parsing logic.

Closes #3118

---

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that changes existing behavior)
• 📝 Documentation update
• ♻️ Refactor / code cleanup (no functional change)
• ⚡ Performance improvement
• 🔒 Security fix
• 🧪 Tests only

---

What Changed

• Updated the ipToNumber utility in src/lib/ssrf-protection.ts to construct IP numbers using safe unsigned multiplication (or >>> 0) instead of signed bitwise shifting.
• This prevents values like 192.168.x.x and 172.16.x.x from wrapping into negative numbers, ensuring they are properly detected and blocked by the private IP range checks.

---

How to Test

1. Attempt to pass 192.168.1.1 to the isPrivateIP check (or attempt to configure a webhook pointing to that IP).
2. Verify that the IP is correctly identified as a private IP (isPrivateIP returns true).
3. Attempt the same with 172.16.0.1 and verify it is also blocked.

Expected result: The vulnerability is patched and requests to internal network services are properly blocked.

---

Screenshots / Recordings

(Not applicable for this backend security fix)

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus