feat: Added Endpoint Integration for CMA Python SDK

[OMpawar-21]

Replaces hardcoded region→host mappings with an Endpoint class backed by the Contentstack Regions Registry. New regions require zero SDK code changes.

Changes

• endpoint.py — new Endpoint class, 3-tier resolution (memory → disk → CDN)
• contentstack.py — Client resolves via Endpoint instead of if/elif chain
• __init__.py — exports Endpoint + module-level get_contentstack_endpoint() proxy
• data/regions.json — bundled registry (gitignored, included in wheel)
• scripts/download_regions.py — refresh registry manually
• 56 new unit tests, ENDPOINT_INTEGRATION.md, changelog

Notes

• Custom host= still overrides resolution — no breaking changes
• Unknown regions fall back to legacy {region}-api.contentstack.com 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	0	10	✅ Passed
🟠 High Severity	0	1	25	✅ Passed
🟡 Medium Severity	0	3	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: 1
• Medium without fixes: 3
• Low without fixes: 0

✅ 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	1	25	✅ Passed
🟡 Medium Severity	0	3	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: 1
• Medium without fixes: 3
• Low without fixes: 0

✅ BUILD PASSED - All security checks passed