docs: Sync MSAL Node and Angular docs with v5 SDK changes

[Dickson-Mwendia]

Summary

This PR synchronizes the MSAL JavaScript Learn documentation with the latest v5 SDK changes for both MSAL Node and MSAL Angular. Changes were identified through an automated audit using the DocGuard skill pipeline (content comparison, API change detection, and freshness analysis).

Changes

MSAL Node

• node/configuration.md — Removed deprecated \proxyUrl, \customAgentOptions, and \skipAuthorityMetadataCache\ options; moved \protocolMode\ to System Config; added migration note
• node/faq.md — Fixed incorrect claim that interactive flow is unsupported (\�cquireTokenInteractive()\ exists in v5); updated proxy and custom agent FAQs; added Node 20+ requirement
• node/v5-migration.md (new) — Migration guide from MSAL Node v3 to v5 with all breaking changes
• node/managed-identity.md (new) — Guide for \ManagedIdentityApplication\ (system-assigned and user-assigned)

MSAL Angular

• angular/configuration.md — Removed deprecated \storeAuthStateInCookie\ and misplaced
  avigateToLoginRequestUrl; added v5 upgrade guide reference
• angular/redirects.md — Added standalone component patterns, \handleRedirectObservable\ options section; removed legacy IE detection code; updated sample references
• angular/msal-interceptor.md — Added strict matching section documenting the v5 default behavior change for \protectedResourceMap\
• angular/v4-v5-upgrade-guide.md (new) — Migration guide from MSAL Angular v4 to v5 (Angular 19, strictMatching, inject tokens)
• angular/v3-v4-upgrade-guide.md (new) — Migration guide from MSAL Angular v3 to v4

Infrastructure

• TOC.yml — Added entries for all 4 new pages
• Added #Customer intent\ metadata to all modified and new files

Audit Findings Addressed

• 7 CRITICAL fixes (removed deprecated APIs, corrected false claims, filled documentation gaps)
• 3 HIGH fixes (stale configuration, missing features)
• 4 MEDIUM fixes (metadata, terminology updates)

Validation

• All changes cross-referenced against SDK source at \AzureAD/microsoft-authentication-library-for-js@dev\
• Customer intent statements placed inside YAML frontmatter per Learn standards
• No auto-generated reference docs modified

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

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[learn-build-service-prod]

Learn Build status updates of commit 38773db:

⚠️ Validation status: warnings

File	Status	Preview URL	Details
msal-javascript-conceptual/angular/v4-v5-upgrade-guide.md	⚠️Warning	View	Details
msal-javascript-conceptual/angular/v3-v4-upgrade-guide.md	💡Suggestion	View	Details
msal-javascript-conceptual/angular/configuration.md	✅Succeeded	View
msal-javascript-conceptual/angular/msal-interceptor.md	✅Succeeded	View
msal-javascript-conceptual/angular/redirects.md	✅Succeeded	View
msal-javascript-conceptual/node/configuration.md	✅Succeeded	View
msal-javascript-conceptual/node/faq.md	✅Succeeded	View
msal-javascript-conceptual/node/managed-identity.md	✅Succeeded	View
msal-javascript-conceptual/node/v5-migration.md	✅Succeeded	View
msal-javascript-conceptual/TOC.yml	✅Succeeded	View

msal-javascript-conceptual/angular/v4-v5-upgrade-guide.md

• Line 19, Column 16: [Warning: file-not-found - See documentation] Invalid file link: '../browser/v4-migration.md'.
• Line 0, Column 0: [Suggestion: filename-incomplete - See documentation] The filename contains an incomplete word, misspelled word, acronym, or abbreviation that is disallowed.

msal-javascript-conceptual/angular/v3-v4-upgrade-guide.md

• Line 0, Column 0: [Suggestion: filename-incomplete - See documentation] The filename contains an incomplete word, misspelled word, acronym, or abbreviation that is disallowed.

For more details, please refer to the build report.

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