fix(licensing): backward-compatible tier/variant enforcement and self-healing variant detection (#385)

Accept legacy tier ('pro') and variant ('personal', 'team') names from older
remote nodes, normalizing them to current values ('paid', 'skipper', 'admiral')
in authMiddleware. This fixes distributed license enforcement failing between
v0.38.3 and v0.38.0 nodes due to the tier rename in v0.38.1.

Also fixes:
- Self-healing getVariant() that cross-checks stored variant_type against
  product/variant name metadata on every call, correcting stale cached values
  from previous buggy resolution logic
- Unguarded API responses in ResourcesView causing potential t.map crashes
- Fleet update status now polls on a 120s interval (was only fetched on mount)
- fetchRemoteMeta failures now logged for diagnosability

backend/src/index.ts

@@ -25,7 +25,7 @@ import { ImageUpdateService } from './services/ImageUpdateService';
 import { templateService } from './services/TemplateService';
 import { ErrorParser } from './utils/ErrorParser';
 import { NodeRegistry } from './services/NodeRegistry';
-import { LicenseService, type LicenseTier, type LicenseVariant, isLicenseTier, isLicenseVariant, PROXY_TIER_HEADER, PROXY_VARIANT_HEADER } from './services/LicenseService';
+import { LicenseService, type LicenseTier, type LicenseVariant, isLicenseTier, isLicenseVariant, normalizeTier, normalizeVariant, PROXY_TIER_HEADER, PROXY_VARIANT_HEADER } from './services/LicenseService';
 import { WebhookService } from './services/WebhookService';
 import { SSOService } from './services/SSOService';
 import { SchedulerService } from './services/SchedulerService';
@@ -310,10 +310,10 @@ const authMiddleware = async (req: Request, res: Response, next: NextFunction):
       const tierHeader = req.headers[PROXY_TIER_HEADER] as string | undefined;
       const variantHeader = req.headers[PROXY_VARIANT_HEADER] as string | undefined;
       if (isLicenseTier(tierHeader)) {
-        req.proxyTier = tierHeader;
+        req.proxyTier = normalizeTier(tierHeader);
       }
       if (isLicenseVariant(variantHeader)) {
-        req.proxyVariant = variantHeader;
+        req.proxyVariant = normalizeVariant(variantHeader);
       } else if (variantHeader === '') {
         req.proxyVariant = null;
       }