feat: add import project API endpoint

internal/dev_server/api/api.yaml

@@ -113,6 +113,28 @@ paths:
           $ref: "#/components/responses/ErrorResponse"
         409:
           $ref: "#/components/responses/ErrorResponse"
+  /projects/{projectKey}/import:
+    post:
+      summary: Import a project from exported JSON data
+      description: |
+        Import a project using the JSON format from get-project with expand options.
+        Accepts the same format that is exported by the get-project endpoint.
+      operationId: postImportProject
+      parameters:
+        - $ref: "#/components/parameters/projectKey"
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/Project"
+      responses:
+        201:
+          $ref: "#/components/responses/Project"
+        400:
+          $ref: "#/components/responses/ErrorResponse"
+        409:
+          $ref: "#/components/responses/ErrorResponse"
   /projects/{projectKey}/overrides:
     delete:
       summary: remove all overrides for the given project

internal/dev_server/api/post_import_project.go

@@ -0,0 +1,82 @@
+package api
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+
+	"github.com/launchdarkly/ldcli/internal/dev_server/model"
+)
+
+func (s server) PostImportProject(ctx context.Context, request PostImportProjectRequestObject) (PostImportProjectResponseObject, error) {
+	// Validate required fields
+	if request.Body.SourceEnvironmentKey == "" {
+		return PostImportProject400JSONResponse{
+			ErrorResponseJSONResponse{
+				Code:    "invalid_request",
+				Message: "sourceEnvironmentKey is required",
+			},
+		}, nil
+	}
+
+	if request.Body.FlagsState == nil || len(*request.Body.FlagsState) == 0 {
+		return PostImportProject400JSONResponse{
+			ErrorResponseJSONResponse{
+				Code:    "invalid_request",
+				Message: "flagsState is required",
+			},
+		}, nil
+	}
+
+	// Build import data from request
+	importData := model.ImportData{
+		Context:              request.Body.Context,
+		SourceEnvironmentKey: request.Body.SourceEnvironmentKey,
+		FlagsState:           *request.Body.FlagsState,
+		Overrides:            request.Body.Overrides,
+	}
+
+	// Convert availableVariations if present
+	if request.Body.AvailableVariations != nil {
+		variations := make(map[string][]model.ImportVariation)
+		for flagKey, vars := range *request.Body.AvailableVariations {
+			for _, v := range vars {
+				variations[flagKey] = append(variations[flagKey], model.ImportVariation{
+					Id:          v.Id,
+					Name:        v.Name,
+					Description: v.Description,
+					Value:       v.Value,
+				})
+			}
+		}
+		importData.AvailableVariations = &variations
+	}
+
+	// Import the project
+	err := model.ImportProject(ctx, request.ProjectKey, importData)
+	switch {
+	case errors.As(err, &model.ErrAlreadyExists{}):
+		return PostImportProject409JSONResponse{
+			Code:    "conflict",
+			Message: err.Error(),
+		}, nil
+	case err != nil:
+		return nil, err
+	}
+
+	// Fetch the imported project to return
+	store := model.StoreFromContext(ctx)
+	project, err := store.GetDevProject(ctx, request.ProjectKey)
+	if err != nil {
+		return nil, err
+	}
+
+	response := ProjectJSONResponse{
+		LastSyncedFromSource: project.LastSyncTime.Unix(),
+		Context:              project.Context,
+		SourceEnvironmentKey: project.SourceEnvironmentKey,
+		FlagsState:           &project.AllFlagsState,
+	}
+
+	return PostImportProject201JSONResponse{response}, nil
+}