Backend, sync, infra, docs: ETag, API versioning, k8s, web scaffold, Android 16, domain stubs

- Backend: ShallowEtagHeaderFilter for /api/v1/*, API-VERSIONING.md, README (tenant, CORS, Flyway, ETag)
- k8s: backend-deployment.yaml (Deployment, Service, Secret/ConfigMap)
- Web: scaffold with directory pull, 304 handling, touch-friendly UI
- Android 16: ANDROID-16-TARGET.md; BuildConfig STUN/signaling, SMOAApplication configures InfrastructureManager
- Domain: CertificateManager revocation stub, ReportService signReports, ZeroTrust/ThreatDetection minimal docs
- TODO.md and IMPLEMENTATION_STATUS.md updated; communications README for endpoint config

Co-authored-by: Cursor <cursoragent@cursor.com>

core/certificates/src/main/java/com/smoa/core/certificates/domain/CertificateManager.kt

@@ -46,10 +46,9 @@ class CertificateManager @Inject constructor() {
     
     /**
      * Check certificate revocation status via OCSP/CRL.
-     * TODO: Implement actual OCSP/CRL checking
+     * Minimal implementation: returns UNKNOWN. Extend with an OCSP client or CRL fetcher for production.
      */
     suspend fun checkRevocationStatus(certificate: X509Certificate): RevocationStatus {
-        // Placeholder - actual implementation will query OCSP responder or CRL
         return RevocationStatus.UNKNOWN
     }
 }