fix: rename SettingsPermissionsGuard to SettingsPermissionGuard for consistency (#15712)

## Problem

The ESLint rule `graphql-resolvers-should-be-guarded` introduced in
#15392 was failing on main because the guard `SettingsPermissionsGuard`
had inconsistent naming.

## Root Cause

The guard was named `SettingsPermissionsGuard` (with an 's') which was
inconsistent with other permission guards:
- ✅ `CustomPermissionGuard`  
- ✅ `NoPermissionGuard`
- ✅ `ImpersonatePermissionGuard`
- ❌ `SettingsPermissionsGuard` (inconsistent!)

The ESLint rule checks if guard names end with `PermissionGuard`, but
`SettingsPermissionsGuard` ends with `sGuard`, so it wasn't recognized
as a permission guard.

## Solution

Renamed the guard to be consistent with the naming convention:

1. ✅ Renamed file: `settings-permissions.guard.ts` →
`settings-permission.guard.ts`
2. ✅ Renamed export: `SettingsPermissionsGuard` →
`SettingsPermissionGuard`
3. ✅ Renamed internal class: `SettingsPermissionsMixin` →
`SettingsPermissionMixin`
4. ✅ Updated all 122 references across 44 files in the codebase
5. ✅ Renamed test file: `settings-permissions.guard.spec.ts` →
`settings-permission.guard.spec.ts`

## Testing

- ✅ `npx nx run twenty-server:lint` passes
- ✅ `npx nx run twenty-server:typecheck` passes
- ✅ No references to the old name remain in the codebase
- ✅ All previously failing resolver files now pass ESLint validation

## Related

Fixes issues introduced in #15392

packages/twenty-server/src/engine/metadata-modules/agent/agent-chat.resolver.ts

@@ -8,7 +8,7 @@ import {
   FeatureFlagGuard,
   RequireFeatureFlag,
 } from 'src/engine/guards/feature-flag.guard';
-import { SettingsPermissionsGuard } from 'src/engine/guards/settings-permissions.guard';
+import { SettingsPermissionGuard } from 'src/engine/guards/settings-permission.guard';
 import { WorkspaceAuthGuard } from 'src/engine/guards/workspace-auth.guard';
 import { AgentChatService } from 'src/engine/metadata-modules/agent/agent-chat.service';
 import { PermissionFlagType } from 'src/engine/metadata-modules/permissions/constants/permission-flag-type.constants';
@@ -19,7 +19,7 @@ import { AgentChatThreadDTO } from './dtos/agent-chat-thread.dto';
 @UseGuards(
   WorkspaceAuthGuard,
   FeatureFlagGuard,
-  SettingsPermissionsGuard(PermissionFlagType.AI),
+  SettingsPermissionGuard(PermissionFlagType.AI),
 )
 @Resolver()
 export class AgentChatResolver {

packages/twenty-server/src/engine/metadata-modules/agent/agent.resolver.ts

@@ -8,7 +8,7 @@ import {
   FeatureFlagGuard,
   RequireFeatureFlag,
 } from 'src/engine/guards/feature-flag.guard';
-import { SettingsPermissionsGuard } from 'src/engine/guards/settings-permissions.guard';
+import { SettingsPermissionGuard } from 'src/engine/guards/settings-permission.guard';
 import { WorkspaceAuthGuard } from 'src/engine/guards/workspace-auth.guard';
 import { CreateAgentHandoffInput } from 'src/engine/metadata-modules/agent/dtos/create-agent-handoff.input';
 import { RemoveAgentHandoffInput } from 'src/engine/metadata-modules/agent/dtos/remove-agent-handoff.input';
@@ -72,7 +72,7 @@ export class AgentResolver {
 
   @Mutation(() => AgentDTO)
   @RequireFeatureFlag(FeatureFlagKey.IS_AI_ENABLED)
-  @UseGuards(SettingsPermissionsGuard(PermissionFlagType.AI_SETTINGS))
+  @UseGuards(SettingsPermissionGuard(PermissionFlagType.AI_SETTINGS))
   async createOneAgent(
     @Args('input') input: CreateAgentInput,
     @AuthWorkspace() { id: workspaceId }: WorkspaceEntity,
@@ -85,7 +85,7 @@ export class AgentResolver {
 
   @Mutation(() => AgentDTO)
   @RequireFeatureFlag(FeatureFlagKey.IS_AI_ENABLED)
-  @UseGuards(SettingsPermissionsGuard(PermissionFlagType.AI_SETTINGS))
+  @UseGuards(SettingsPermissionGuard(PermissionFlagType.AI_SETTINGS))
   async updateOneAgent(
     @Args('input') input: UpdateAgentInput,
     @AuthWorkspace() { id: workspaceId }: WorkspaceEntity,
@@ -95,7 +95,7 @@ export class AgentResolver {
 
   @Mutation(() => AgentDTO)
   @RequireFeatureFlag(FeatureFlagKey.IS_AI_ENABLED)
-  @UseGuards(SettingsPermissionsGuard(PermissionFlagType.AI_SETTINGS))
+  @UseGuards(SettingsPermissionGuard(PermissionFlagType.AI_SETTINGS))
   async deleteOneAgent(
     @Args('input') { id }: AgentIdInput,
     @AuthWorkspace() { id: workspaceId }: WorkspaceEntity,
@@ -105,7 +105,7 @@ export class AgentResolver {
 
   @Mutation(() => Boolean)
   @RequireFeatureFlag(FeatureFlagKey.IS_AI_ENABLED)
-  @UseGuards(SettingsPermissionsGuard(PermissionFlagType.AI_SETTINGS))
+  @UseGuards(SettingsPermissionGuard(PermissionFlagType.AI_SETTINGS))
   async createAgentHandoff(
     @Args('input') input: CreateAgentHandoffInput,
     @AuthWorkspace() { id: workspaceId }: WorkspaceEntity,
@@ -122,7 +122,7 @@ export class AgentResolver {
 
   @Mutation(() => Boolean)
   @RequireFeatureFlag(FeatureFlagKey.IS_AI_ENABLED)
-  @UseGuards(SettingsPermissionsGuard(PermissionFlagType.AI_SETTINGS))
+  @UseGuards(SettingsPermissionGuard(PermissionFlagType.AI_SETTINGS))
   async removeAgentHandoff(
     @Args('input') input: RemoveAgentHandoffInput,
     @AuthWorkspace() { id: workspaceId }: WorkspaceEntity,