refactor: standardize AI acronym to Ai (PascalCase) across internal identifiers (#19837)

## Summary

The "AI" acronym was rendered inconsistently across the codebase. The
backend AI module had settled on PascalCase `Ai` (`AiAgentModule`,
`AiBillingService`, `AiChatModule`, `AiModelRegistryService`, etc.),
while frontend components, several DTOs, a few types, and shared
identifiers still used all-caps `AI` (`AIChatTab`,
`AISystemPromptPreviewDTO`, `SettingsPath.AIPrompts`, ...). CLAUDE.md
specifies PascalCase for classes; this PR normalizes everything internal
to `Ai`.

**This is a pure internal rename.** The GraphQL schema is untouched —
`@ObjectType` decorator string arguments, resolver method names (which
become Query/Mutation field names), gql template contents, and the
`generated-metadata/graphql.ts` file are preserved verbatim. The only
visible change is TypeScript identifiers and file names.

## Also folded in (adjacent cleanups)

- **`AgentModelConfigService` → `AiModelConfigService`**. Lives in
`ai-models/` and is used by multiple AI code paths, not just the Agent
entity. The "Agent" prefix was misleading.
- **`generate-text-input.dto.ts` → `generate-text.input.ts`**. The
`ai-agent/dtos/` folder already uses `<entity>.input.ts` convention for
Input classes (`create-agent.input.ts` etc.); the old path mixed
`.dto.ts` file extension with a class that has no DTO suffix. File
rename only; class stays `GenerateTextInput`.
- **Removed stale TODO** in `ai-model-config.type.ts` that asked for the
`AiModelConfig` rename that this PR performs.

## Rename methodology

Bulk rename via perl with anchored regex
`(?<!['"])(?<![A-Z.])AI([A-Z])(?=[a-z])/Ai$1/g`:

- **Lookbehind for non-uppercase** skips adjacent acronyms (`MOSAIC`,
`OIDCSSO`) and leaves `AIRBNB_ID` alone.
- **Lookbehind for non-quote** protects most string literals.
- **Lookahead for lowercase** restricts matches to PascalCase
identifiers (`AIChatTab`), leaving SCREAMING_SNAKE constants untouched.

Strict file-scope exclusions: `generated-metadata/**`, `generated/**`,
`locales/**`, `migrations/**`, `illustrations/**`, `halftone/**`, and
the two gql template files (`queries/getAISystemPromptPreview.ts`,
`mutations/uploadAIChatFile.ts`).

Post-rename reverts for identifiers where the regex was too eager:
- Backend resolver method names kept: `getAISystemPromptPreview`,
`uploadAIChatFile` (they are GraphQL field names).
- `@ObjectType('AdminAIModels')` / `('AISystemPromptPreview')` /
`('AISystemPromptSection')` kept as-is.
- Backend classes `ClientAIModelConfig` / `AdminAIModelConfig` kept
as-is (they use `@ObjectType()` with no argument, so the class name IS
the schema name).
- External-library symbols restored: `OpenAIProvider`,
`createOpenAICompatible`, `vercelAIIntegration`.

File renames use a two-step rename to work on macOS case-insensitive
filesystems: `git mv X.tsx X.tsx.tmp && git mv X.tsx.tmp renamed.tsx`.

## Diff audit

- 0 changes to migrations
- 0 changes to locale `.po` / `.ts` files
- 0 changes to `generated-metadata/graphql.ts`
- 0 changes to website illustration files (base64 blobs preserved)
- 0 renames inside user-facing translation strings (`t\`…\``,
`msg\`…\``, `<Trans>…</Trans>`)

## Test plan

- [x] `npx nx typecheck twenty-server` — PASS
- [x] `npx nx typecheck twenty-front` — PASS
- [x] `npx jest ai-model admin agent-role` — 79/79 PASS
- [x] `npx oxlint --type-aware` on 118 changed files — 0 errors
- [x] `npx prettier --check` on 118 changed files — clean
- [ ] CI

packages/twenty-server/src/engine/core-modules/file/file-ai-chat/file-ai-chat.module.ts

@@ -1,14 +1,14 @@
 import { Module } from '@nestjs/common';
 
 import { ApplicationModule } from 'src/engine/core-modules/application/application.module';
-import { FileAIChatResolver } from 'src/engine/core-modules/file/file-ai-chat/resolvers/file-ai-chat.resolver';
-import { FileAIChatService } from 'src/engine/core-modules/file/file-ai-chat/services/file-ai-chat.service';
+import { FileAiChatResolver } from 'src/engine/core-modules/file/file-ai-chat/resolvers/file-ai-chat.resolver';
+import { FileAiChatService } from 'src/engine/core-modules/file/file-ai-chat/services/file-ai-chat.service';
 import { FileUrlModule } from 'src/engine/core-modules/file/file-url/file-url.module';
 import { PermissionsModule } from 'src/engine/metadata-modules/permissions/permissions.module';
 
 @Module({
   imports: [FileUrlModule, ApplicationModule, PermissionsModule],
-  providers: [FileAIChatService, FileAIChatResolver],
-  exports: [FileAIChatService],
+  providers: [FileAiChatService, FileAiChatResolver],
+  exports: [FileAiChatService],
 })
-export class FileAIChatModule {}
+export class FileAiChatModule {}

packages/twenty-server/src/engine/core-modules/file/file-ai-chat/resolvers/file-ai-chat.resolver.ts

@@ -8,7 +8,7 @@ import type { FileUpload } from 'graphql-upload/processRequest.mjs';
 
 import { MetadataResolver } from 'src/engine/api/graphql/graphql-config/decorators/metadata-resolver.decorator';
 import { FileWithSignedUrlDTO } from 'src/engine/core-modules/file/dtos/file-with-sign-url.dto';
-import { FileAIChatService } from 'src/engine/core-modules/file/file-ai-chat/services/file-ai-chat.service';
+import { FileAiChatService } from 'src/engine/core-modules/file/file-ai-chat/services/file-ai-chat.service';
 import { PreventNestToAutoLogGraphqlErrorsFilter } from 'src/engine/core-modules/graphql/filters/prevent-nest-to-auto-log-graphql-errors.filter';
 import { ResolverValidationPipe } from 'src/engine/core-modules/graphql/pipes/resolver-validation.pipe';
 import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.entity';
@@ -21,12 +21,12 @@ import { streamToBuffer } from 'src/utils/stream-to-buffer';
 @UsePipes(ResolverValidationPipe)
 @UseFilters(PreventNestToAutoLogGraphqlErrorsFilter)
 @MetadataResolver()
-export class FileAIChatResolver {
-  constructor(private readonly fileAIChatService: FileAIChatService) {}
+export class FileAiChatResolver {
+  constructor(private readonly fileAiChatService: FileAiChatService) {}
 
   @Mutation(() => FileWithSignedUrlDTO)
   @UseGuards(SettingsPermissionGuard(PermissionFlagType.UPLOAD_FILE))
-  async uploadAIChatFile(
+  async uploadAiChatFile(
     @AuthWorkspace()
     { id: workspaceId }: WorkspaceEntity,
     @Args({ name: 'file', type: () => GraphQLUpload })
@@ -35,7 +35,7 @@ export class FileAIChatResolver {
     const stream = createReadStream();
     const buffer = await streamToBuffer(stream);
 
-    return await this.fileAIChatService.uploadFile({
+    return await this.fileAiChatService.uploadFile({
       file: buffer,
       filename,
       workspaceId,

packages/twenty-server/src/engine/core-modules/file/file-ai-chat/services/file-ai-chat.service.ts

@@ -11,7 +11,7 @@ import { FileUrlService } from 'src/engine/core-modules/file/file-url/file-url.s
 import { extractFileInfo } from 'src/engine/core-modules/file/utils/extract-file-info.utils';
 import { sanitizeFile } from 'src/engine/core-modules/file/utils/sanitize-file.utils';
 @Injectable()
-export class FileAIChatService {
+export class FileAiChatService {
   constructor(
     private readonly fileStorageService: FileStorageService,
     private readonly applicationService: ApplicationService,

packages/twenty-server/src/engine/core-modules/file/file.module.ts

@@ -3,7 +3,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 
 import { ApplicationEntity } from 'src/engine/core-modules/application/application.entity';
 import { FileStorageModule } from 'src/engine/core-modules/file-storage/file-storage.module';
-import { FileAIChatModule } from 'src/engine/core-modules/file/file-ai-chat/file-ai-chat.module';
+import { FileAiChatModule } from 'src/engine/core-modules/file/file-ai-chat/file-ai-chat.module';
 import { FilePathGuard } from 'src/engine/core-modules/file/guards/file-path-guard';
 import { FileDeletionJob } from 'src/engine/core-modules/file/jobs/file-deletion.job';
 import { FileWorkspaceFolderDeletionJob } from 'src/engine/core-modules/file/jobs/file-workspace-folder-deletion.job';
@@ -34,7 +34,7 @@ import { FileService } from './services/file.service';
     FilesFieldModule,
     FileCorePictureModule,
     FileWorkflowModule,
-    FileAIChatModule,
+    FileAiChatModule,
     FileEmailAttachmentModule,
     SecureHttpClientModule,
   ],
@@ -53,7 +53,7 @@ import { FileService } from './services/file.service';
     FilesFieldModule,
     FileCorePictureModule,
     FileWorkflowModule,
-    FileAIChatModule,
+    FileAiChatModule,
     FileEmailAttachmentModule,
   ],
   controllers: [FileController],