diff --git a/frontends/nextjs/src/app/[tenant]/[package]/[...slug]/page.tsx b/frontends/nextjs/src/app/[tenant]/[package]/[...slug]/page.tsx
index c447b1ddb..131c81441 100644
--- a/frontends/nextjs/src/app/[tenant]/[package]/[...slug]/page.tsx
+++ b/frontends/nextjs/src/app/[tenant]/[package]/[...slug]/page.tsx
@@ -36,9 +36,9 @@ export default async function EntityPage({ params }: EntityPageProps) {
   
   if (id === 'new') {
     viewType = 'create'
-  } else if (id && action === 'edit') {
+  } else if (id !== null && id !== undefined && action === 'edit') {
     viewType = 'edit'
-  } else if (id) {
+  } else if (id !== null && id !== undefined) {
     viewType = 'detail'
   }
 
@@ -49,7 +49,7 @@ export default async function EntityPage({ params }: EntityPageProps) {
           <a href={`/${tenant}/${pkg}`}>{pkg}</a>
           {' / '}
           <span>{entity}</span>
-          {id && id !== 'new' && (
+          {(id !== null && id !== undefined) && id !== 'new' && (
             <>
               {' / '}
               <span>{id}</span>
@@ -69,12 +69,12 @@ export default async function EntityPage({ params }: EntityPageProps) {
           />
         )}
         
-        {viewType === 'detail' && (
+        {viewType === 'detail' && id !== null && id !== undefined && (
           <EntityDetailView 
             tenant={tenant} 
             pkg={pkg} 
             entity={entity} 
-            id={id!}
+            id={id}
           />
         )}
         
@@ -86,12 +86,12 @@ export default async function EntityPage({ params }: EntityPageProps) {
           />
         )}
         
-        {viewType === 'edit' && (
+        {viewType === 'edit' && id !== null && id !== undefined && (
           <EntityEditView 
             tenant={tenant} 
             pkg={pkg} 
             entity={entity} 
-            id={id!}
+            id={id}
           />
         )}
       </main>
@@ -202,13 +202,13 @@ function EntityEditView({ tenant, pkg, entity, id }: {
 
 export async function generateMetadata({ params }: EntityPageProps) {
   const { tenant, package: pkg, slug } = await params
-  const entity = slug?.[0] || 'unknown'
+  const entity = slug?.[0] ?? 'unknown'
   const id = slug?.[1]
   
   let title = `${entity} - ${pkg}`
   if (id === 'new') {
     title = `New ${entity} - ${pkg}`
-  } else if (id) {
+  } else if (id !== null && id !== undefined) {
     title = `${entity} #${id} - ${pkg}`
   }
   
diff --git a/frontends/nextjs/src/app/[tenant]/[package]/tenant-context.tsx b/frontends/nextjs/src/app/[tenant]/[package]/tenant-context.tsx
index 3344b6a56..0957b81de 100644
--- a/frontends/nextjs/src/app/[tenant]/[package]/tenant-context.tsx
+++ b/frontends/nextjs/src/app/[tenant]/[package]/tenant-context.tsx
@@ -84,10 +84,10 @@ export function TenantProvider({
     getTableName: (entity: string) => getTableName(packageId, entity),
     
     buildApiUrl: (entity: string, id?: string, action?: string, pkg?: string) => {
-      const targetPkg = pkg || packageId
+      const targetPkg = pkg ?? packageId
       let url = `/api/v1/${tenant}/${targetPkg}/${entity}`
-      if (id) url += `/${id}`
-      if (action) url += `/${action}`
+      if (id !== null && id !== undefined) url += `/${id}`
+      if (action !== null && action !== undefined) url += `/${action}`
       return url
     },
     
@@ -110,7 +110,7 @@ export function TenantProvider({
 export function useTenant(): TenantContextValue {
   const context = useContext(TenantContext)
   
-  if (!context) {
+  if (context === null || context === undefined) {
     throw new Error('useTenant must be used within a TenantProvider')
   }
   
diff --git a/frontends/nextjs/src/app/api/dbal/schema/route.ts b/frontends/nextjs/src/app/api/dbal/schema/route.ts
index d5641d3f4..da41b49dd 100644
--- a/frontends/nextjs/src/app/api/dbal/schema/route.ts
+++ b/frontends/nextjs/src/app/api/dbal/schema/route.ts
@@ -23,7 +23,7 @@ const getPrismaOutputPath = () => path.join(process.cwd(), '..', '..', '..', 'pr
  * Note: This endpoint is for admin/system use.
  * For tenant-scoped data, use /api/v1/{tenant}/{package}/{entity}
  */
-export async function GET() {
+export function GET() {
   try {
     const registryPath = getRegistryPath()
     const registry = loadSchemaRegistry(registryPath)
@@ -92,7 +92,7 @@ export async function POST(request: Request) {
   }
 }
 
-async function handleScan(registry: SchemaRegistry, registryPath: string) {
+function handleScan(registry: SchemaRegistry, registryPath: string) {
   // TODO: Import scanAllPackages when schema-scanner is implemented
   // const { scanAllPackages } = await import('@/lib/schema/schema-scanner')
   // const result = await scanAllPackages(registry)
@@ -113,7 +113,7 @@ function handleGenerate(registry: SchemaRegistry) {
   const fragment = generatePrismaFragment(registry)
   const prismaOutputPath = getPrismaOutputPath()
   
-  if (!fragment.trim()) {
+  if (fragment.trim().length === 0) {
     return NextResponse.json({
       status: 'ok',
       action: 'generate',
@@ -135,7 +135,7 @@ function handleGenerate(registry: SchemaRegistry) {
 }
 
 function handleApprove(registry: SchemaRegistry, registryPath: string, id?: string) {
-  if (!id) {
+  if (id === null || id === undefined) {
     return NextResponse.json(
       { status: 'error', error: 'Migration ID required' },
       { status: 400 }
diff --git a/frontends/nextjs/src/lib/db/error-logs/crud/add-error-log.ts b/frontends/nextjs/src/lib/db/error-logs/crud/add-error-log.ts
index 768502e75..9d9722593 100644
--- a/frontends/nextjs/src/lib/db/error-logs/crud/add-error-log.ts
+++ b/frontends/nextjs/src/lib/db/error-logs/crud/add-error-log.ts
@@ -13,15 +13,15 @@ export async function addErrorLog(log: Omit<ErrorLog, 'id'>): Promise<string> {
     timestamp: BigInt(log.timestamp),
     level: log.level,
     message: log.message,
-    stack: log.stack || null,
-    context: log.context || null,
-    userId: log.userId || null,
-    username: log.username || null,
-    tenantId: log.tenantId || null,
-    source: log.source || null,
+    stack: log.stack ?? null,
+    context: log.context ?? null,
+    userId: log.userId ?? null,
+    username: log.username ?? null,
+    tenantId: log.tenantId ?? null,
+    source: log.source ?? null,
     resolved: log.resolved,
-    resolvedAt: log.resolvedAt ? BigInt(log.resolvedAt) : null,
-    resolvedBy: log.resolvedBy || null,
+    resolvedAt: log.resolvedAt !== null && log.resolvedAt !== undefined ? BigInt(log.resolvedAt) : null,
+    resolvedBy: log.resolvedBy ?? null,
   })
 
   return id
diff --git a/frontends/nextjs/src/lib/db/god-credentials/index.ts b/frontends/nextjs/src/lib/db/god-credentials/index.ts
index faed1ba68..44fc29008 100644
--- a/frontends/nextjs/src/lib/db/god-credentials/index.ts
+++ b/frontends/nextjs/src/lib/db/god-credentials/index.ts
@@ -6,9 +6,8 @@ import { getAdapter } from '../core/dbal-client'
 export async function getGodCredentialsExpiry(): Promise<number> {
   const adapter = getAdapter()
   const result = await adapter.list('SystemConfig')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const config = (result.data as any[]).find((c: any) => c.key === 'godCredentialsExpiry')
-  return config?.value ? Number(config.value) : 0
+  const config = (result.data as Array<{ key: string; value?: string }>).find((c) => c.key === 'godCredentialsExpiry')
+  return (config?.value !== null && config?.value !== undefined) ? Number(config.value) : 0
 }
 
 /**
@@ -31,11 +30,10 @@ export async function setGodCredentialsExpiry(timestamp: number): Promise<void>
 export async function getFirstLoginFlags(): Promise<Record<string, boolean>> {
   const adapter = getAdapter()
   const result = await adapter.list('User')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const users = result.data as any[]
+  const users = result.data as Array<{ id?: string; firstLogin?: boolean }>
   const flags: Record<string, boolean> = {}
   for (const user of users) {
-    if (user.id && user.firstLogin !== undefined) {
+    if (user.id !== null && user.id !== undefined && user.firstLogin !== undefined) {
       flags[user.id] = Boolean(user.firstLogin)
     }
   }
@@ -56,9 +54,8 @@ export async function setFirstLoginFlag(userId: string, flag: boolean): Promise<
 export async function getGodCredentialsExpiryDuration(): Promise<number> {
   const adapter = getAdapter()
   const result = await adapter.list('SystemConfig')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const config = (result.data as any[]).find((c: any) => c.key === 'godCredentialsExpiryDuration')
-  return config?.value ? Number(config.value) : 300000 // Default 5 minutes
+  const config = (result.data as Array<{ key: string; value?: string }>).find((c) => c.key === 'godCredentialsExpiryDuration')
+  return (config?.value !== null && config?.value !== undefined) ? Number(config.value) : 300000 // Default 5 minutes
 }
 
 /**