fix: bump 8 deps and add nanoid override to resolve Snyk vulnerabilities

[cs-raj]

Summary

Resolves all actionable Snyk SCA vulnerabilities (2 critical, 4 high → 0).

Direct dependency changes

Package	Before	After
next	^16.2.12	^16.3.3
@contentstack/delivery-sdk	^5.2.2	^5.6.0
@contentstack/live-preview-utils	^4.4.4	^4.5.0
isomorphic-dompurify	^3.18.0	^3.23.0
react	^19.2.7	^19.2.8
react-dom	^19.2.7	^19.2.8
lightningcss-linux-x64-gnu	1.32.0	1.33.0
lightningcss-linux-x64-musl	1.32.0	1.33.0

Overrides

Package	Before	After	Reason
nanoid	3.3.17	3.3.18	Fixes GHSA-2v37-7h3g-55p8 (high) via @tailwindcss/postcss → postcss chain

Vulnerability counts

Scanner	Before	After	Fixed
Snyk critical	2	0	✓ 2 (next: Directory Traversal + Insecure Automated Optimizations)
npm audit high	4	0	✓ 4 (nanoid → postcss chain)

Remaining

• 22 LGPL license notices (@img/sharp-*, lightningcss-*) — no fix available, informational only
• Snyk Code findings — source-level static analysis, unaffected by dep updates
• Package version bumped: 1.0.15 → 1.0.16

Build note

Local build blocked by Node v18.20.8 — next@16.3.3 requires >=20.9.0. This is a pre-existing environment constraint, not a regression from these changes. CI/prod environments running Node ≥20 are unaffected.

[snyk-io]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues
✅	Code Security	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[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	22	500	✅ Passed
🔵 Low Severity	0	0	1000	✅ 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

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: 22
• Low without fixes: 0

✅ BUILD PASSED - All security checks passed