feat(api): add terminal session persistence with Prisma model and CRUD (#517)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/terminal/terminal-session.dto.ts

@@ -0,0 +1,53 @@
+/**
+ * Terminal Session DTOs
+ *
+ * Data Transfer Objects for terminal session persistence endpoints.
+ * Validated using class-validator decorators.
+ */
+
+import { IsString, IsOptional, MaxLength, IsEnum, IsUUID } from "class-validator";
+import { TerminalSessionStatus } from "@prisma/client";
+
+/**
+ * DTO for creating a new terminal session record.
+ */
+export class CreateTerminalSessionDto {
+  @IsString()
+  @IsUUID()
+  workspaceId!: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(128)
+  name?: string;
+}
+
+/**
+ * DTO for querying terminal sessions by workspace.
+ */
+export class FindTerminalSessionsByWorkspaceDto {
+  @IsString()
+  @IsUUID()
+  workspaceId!: string;
+}
+
+/**
+ * Response shape for a terminal session.
+ */
+export class TerminalSessionResponseDto {
+  id!: string;
+  workspaceId!: string;
+  name!: string;
+  status!: TerminalSessionStatus;
+  createdAt!: Date;
+  closedAt!: Date | null;
+}
+
+/**
+ * DTO for filtering terminal sessions by status.
+ */
+export class TerminalSessionStatusFilterDto {
+  @IsOptional()
+  @IsEnum(TerminalSessionStatus)
+  status?: TerminalSessionStatus;
+}