feat: add tenant entity, repository, and database migration

Tenants table with slug, tier (LOW/MID/HIGH/BUSINESS), status
(PROVISIONING/ACTIVE/SUSPENDED/DELETED), Logto org reference, and
Stripe IDs.

src/main/java/net/siegeln/cameleer/saas/tenant/TenantEntity.java

@@ -0,0 +1,92 @@
+package net.siegeln.cameleer.saas.tenant;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.PrePersist;
+import jakarta.persistence.PreUpdate;
+import jakarta.persistence.Table;
+import org.hibernate.annotations.JdbcTypeCode;
+import org.hibernate.type.SqlTypes;
+
+import java.time.Instant;
+import java.util.Map;
+import java.util.UUID;
+
+@Entity
+@Table(name = "tenants")
+public class TenantEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.UUID)
+    private UUID id;
+
+    @Column(name = "name", nullable = false)
+    private String name;
+
+    @Column(name = "slug", nullable = false, unique = true, length = 100)
+    private String slug;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "tier", nullable = false, length = 20)
+    private Tier tier = Tier.LOW;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "status", nullable = false, length = 20)
+    private TenantStatus status = TenantStatus.PROVISIONING;
+
+    @Column(name = "logto_org_id")
+    private String logtoOrgId;
+
+    @Column(name = "stripe_customer_id")
+    private String stripeCustomerId;
+
+    @Column(name = "stripe_subscription_id")
+    private String stripeSubscriptionId;
+
+    @JdbcTypeCode(SqlTypes.JSON)
+    @Column(name = "settings", columnDefinition = "jsonb")
+    private Map<String, Object> settings = Map.of();
+
+    @Column(name = "created_at", nullable = false, updatable = false)
+    private Instant createdAt;
+
+    @Column(name = "updated_at", nullable = false)
+    private Instant updatedAt;
+
+    @PrePersist
+    protected void onCreate() {
+        Instant now = Instant.now();
+        if (createdAt == null) createdAt = now;
+        if (updatedAt == null) updatedAt = now;
+    }
+
+    @PreUpdate
+    protected void onUpdate() {
+        updatedAt = Instant.now();
+    }
+
+    public UUID getId() { return id; }
+    public String getName() { return name; }
+    public void setName(String name) { this.name = name; }
+    public String getSlug() { return slug; }
+    public void setSlug(String slug) { this.slug = slug; }
+    public Tier getTier() { return tier; }
+    public void setTier(Tier tier) { this.tier = tier; }
+    public TenantStatus getStatus() { return status; }
+    public void setStatus(TenantStatus status) { this.status = status; }
+    public String getLogtoOrgId() { return logtoOrgId; }
+    public void setLogtoOrgId(String logtoOrgId) { this.logtoOrgId = logtoOrgId; }
+    public String getStripeCustomerId() { return stripeCustomerId; }
+    public void setStripeCustomerId(String stripeCustomerId) { this.stripeCustomerId = stripeCustomerId; }
+    public String getStripeSubscriptionId() { return stripeSubscriptionId; }
+    public void setStripeSubscriptionId(String stripeSubscriptionId) { this.stripeSubscriptionId = stripeSubscriptionId; }
+    public Map<String, Object> getSettings() { return settings; }
+    public void setSettings(Map<String, Object> settings) { this.settings = settings; }
+    public Instant getCreatedAt() { return createdAt; }
+    public Instant getUpdatedAt() { return updatedAt; }
+}

src/main/java/net/siegeln/cameleer/saas/tenant/TenantRepository.java

@@ -0,0 +1,16 @@
+package net.siegeln.cameleer.saas.tenant;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+@Repository
+public interface TenantRepository extends JpaRepository<TenantEntity, UUID> {
+    Optional<TenantEntity> findBySlug(String slug);
+    Optional<TenantEntity> findByLogtoOrgId(String logtoOrgId);
+    List<TenantEntity> findByStatus(TenantStatus status);
+    boolean existsBySlug(String slug);
+}

src/main/java/net/siegeln/cameleer/saas/tenant/TenantStatus.java

@@ -0,0 +1,5 @@
+package net.siegeln.cameleer.saas.tenant;
+
+public enum TenantStatus {
+    PROVISIONING, ACTIVE, SUSPENDED, DELETED
+}

src/main/java/net/siegeln/cameleer/saas/tenant/Tier.java

@@ -0,0 +1,5 @@
+package net.siegeln.cameleer.saas.tenant;
+
+public enum Tier {
+    LOW, MID, HIGH, BUSINESS
+}

src/main/resources/db/migration/V005__create_tenants.sql

@@ -0,0 +1,17 @@
+CREATE TABLE tenants (
+    id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name            VARCHAR(255) NOT NULL,
+    slug            VARCHAR(100) NOT NULL UNIQUE,
+    tier            VARCHAR(20) NOT NULL DEFAULT 'LOW',
+    status          VARCHAR(20) NOT NULL DEFAULT 'PROVISIONING',
+    logto_org_id    VARCHAR(255),
+    stripe_customer_id     VARCHAR(255),
+    stripe_subscription_id VARCHAR(255),
+    settings        JSONB NOT NULL DEFAULT '{}',
+    created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_tenants_slug ON tenants (slug);
+CREATE INDEX idx_tenants_status ON tenants (status);
+CREATE INDEX idx_tenants_logto_org_id ON tenants (logto_org_id);