feat: Sprint 14 — Marketing & Monetization

- Landing page with hero, feature grid, trust signals
- Split-layout login redesign (admin + portal)
- Pricing page with storage tiers (5GB/50GB/unlimited)
- StorageQuotaService backend (V36 migration, 402 on exceeded)
- Frontend storage integration + 402 error handling
- StorageController uses TenantContext for tenant isolation
- onTierChange() hook for subscription tier updates

cannamanage-api/src/main/java/de/cannamanage/api/controller/StorageController.java

@@ -0,0 +1,34 @@
+package de.cannamanage.api.controller;
+
+import de.cannamanage.domain.entity.TenantContext;
+import de.cannamanage.service.StorageQuotaService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+/**
+ * REST controller for storage quota information.
+ * Provides endpoint to check current storage usage for the caller's club.
+ * Club ID is extracted from the JWT/tenant context — not from request params.
+ */
+@RestController
+@RequestMapping("/api/v1/storage")
+@PreAuthorize("hasAnyRole('ADMIN', 'STAFF')")
+public class StorageController {
+
+    private final StorageQuotaService storageQuotaService;
+
+    public StorageController(StorageQuotaService storageQuotaService) {
+        this.storageQuotaService = storageQuotaService;
+    }
+
+    @GetMapping("/usage")
+    public ResponseEntity<StorageQuotaService.StorageUsageDTO> getUsage() {
+        UUID clubId = TenantContext.getCurrentTenant();
+        return ResponseEntity.ok(storageQuotaService.getUsage(clubId));
+    }
+}

cannamanage-api/src/main/java/de/cannamanage/api/exception/GlobalExceptionHandler.java

@@ -5,6 +5,7 @@ import de.cannamanage.service.exception.BatchNotFoundException;
 import de.cannamanage.service.exception.MemberNotFoundException;
 import de.cannamanage.service.exception.PreventionOfficerLimitExceededException;
 import de.cannamanage.service.exception.QuotaExceededException;
+import de.cannamanage.service.exception.StorageQuotaExceededException;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ProblemDetail;
@@ -121,6 +122,20 @@ public class GlobalExceptionHandler {
         return problem;
     }
 
+    @ExceptionHandler(StorageQuotaExceededException.class)
+    public ProblemDetail handleStorageQuotaExceeded(StorageQuotaExceededException ex) {
+        ProblemDetail problem = ProblemDetail.forStatusAndDetail(
+                HttpStatus.PAYMENT_REQUIRED, ex.getMessage());
+        problem.setTitle("Storage Quota Exceeded");
+        problem.setType(URI.create("urn:cannamanage:error:STORAGE_QUOTA_EXCEEDED"));
+        problem.setProperty("code", "STORAGE_QUOTA_EXCEEDED");
+        problem.setProperty("currentUsage", ex.getCurrentUsage());
+        problem.setProperty("limit", ex.getLimit());
+        problem.setProperty("requestedBytes", ex.getRequestedBytes());
+        problem.setProperty("timestamp", Instant.now().toString());
+        return problem;
+    }
+
     @ExceptionHandler(ResponseStatusException.class)
     public ProblemDetail handleResponseStatus(ResponseStatusException ex) {
         ProblemDetail problem = ProblemDetail.forStatusAndDetail(

cannamanage-api/src/main/resources/db/migration/V36__storage_quota.sql

@@ -0,0 +1,9 @@
+-- V36: Add storage quota tracking to clubs
+ALTER TABLE clubs ADD COLUMN IF NOT EXISTS storage_used_bytes BIGINT DEFAULT 0;
+ALTER TABLE clubs ADD COLUMN IF NOT EXISTS storage_limit_bytes BIGINT DEFAULT 5368709120;
+-- Default: 5 GB (5 * 1024^3) = Starter tier
+
+-- Backfill existing clubs with actual usage
+UPDATE clubs c SET storage_used_bytes = COALESCE(
+    (SELECT SUM(d.file_size) FROM documents d WHERE d.club_id = c.id), 0
+);