feat: add support for AM in import module

[naman-contentstack]

Import: Asset Management (AM 2.0) integration

Adds support for AM 2.0–style exports alongside the legacy asset flow in @contentstack/cli-cm-import.

• Detection: Enables the AM path when the export includes spaces/ and stack metadata indicates am_v2 (see import-config-handler).
• Orchestration: contentstack-import delegates space creation, folder/asset upload, org-level fields/asset types, and mapper output to @contentstack/cli-asset-management.
• Mappers: Writes mapper/assets/uid-mapping.json, url-mapping.json, and space-uid-mapping.json for entries resolution (pending requests + throughput charts use GCP metrics; URLs map old AM direct URLs → new).
• Stack linking: Links imported spaces to the target stack via branch settings (stack.branch(uid).updateSettings / am_v2.linked_workspaces) after mappers are written.
• UX: Quantification queue UI: dual-axis charts, shared graph height, refresh button loading state, English copy.

Requires: @contentstack/management with branch updateSettings; region assetManagementUrl for AM API calls.

[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	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

✅ BUILD PASSED - All security checks passed