feat: add load-chalk hook to initialize chalk for CLI commands

[harshitha-cstk]

Summary
Resolves Chalk not loaded. Ensure loadChalk() is called during init when running stack export / import (and similar flows) under pnpm, where the core CLI and a registry plugin can each resolve a different physical copy of @contentstack/cli-utilities at the same version. loadChalk() ran on one copy (core utils-init); getChalk() ran on the other (plugin), so the plugin’s module never had chalk initialized.

Changes
@contentstack/cli-utilities (chalk.ts)
Keep loadChalk() / getChalk() as the public API (no changes required in other packages).
Store the loaded chalk module on globalThis using Symbol.for('@contentstack/cli-utilities/chalk') so every copy of this package in the process shares one cache after loadChalk() runs once (e.g. from core utils-init).
Use local variable name chalkInstance throughout for clarity and consistency with the previous module-scoped pattern.

[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	261	10	✅ Passed
🟠 High Severity	2	210	25	✅ Passed
🟡 Medium Severity	0	696	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: 261
• High without fixes: 210
• Medium without fixes: 696
• Low without fixes: 0

✅ BUILD PASSED - All security checks passed