diff --git a/api-refactoring-final.md b/api-refactoring-final.md
index e3f945d..c399e8d 100644
--- a/api-refactoring-final.md
+++ b/api-refactoring-final.md
@@ -84,27 +84,34 @@ Project is in active development with no existing clients. All changes can be ma
 1. **Rename field:** `enhancedPrompt` → `originalPrompt`
 2. **Change field semantics:**
    - `prompt` - ALWAYS contains the prompt that was used for generation (enhanced or original)
-   - `originalPrompt` - contains user's original input ONLY if autoEnhance was used (nullable)
+   - `originalPrompt` - ALWAYS contains user's original input (for transparency and audit trail)
 
 **Field population logic:**
 
 ```
 Case 1: autoEnhance = false
   prompt = user input
-  originalPrompt = NULL
+  originalPrompt = user input (same value, preserved for consistency)
 
 Case 2: autoEnhance = true
   prompt = enhanced prompt (used for generation)
   originalPrompt = user input (preserved)
 ```
 
+**Rationale:** Always storing `originalPrompt` provides:
+- Audit trail of user's actual input
+- Ability to compare original vs enhanced prompts
+- Consistent API response structure
+- Simplified client logic (no null checks needed)
+
 ### 2.2 API Response Format
 
 **Response structure:**
 ```json
 {
   "prompt": "detailed enhanced prompt...",  // Always the prompt used for generation
-  "originalPrompt": "sunset"                // Only present if enhancement was used
+  "originalPrompt": "sunset",               // Always the user's original input
+  "autoEnhance": true                       // True if prompt differs from originalPrompt
 }
 ```
 
diff --git a/apps/api-service/src/routes/v1/flows.ts b/apps/api-service/src/routes/v1/flows.ts
index 4f37d59..4772d0d 100644
--- a/apps/api-service/src/routes/v1/flows.ts
+++ b/apps/api-service/src/routes/v1/flows.ts
@@ -472,28 +472,28 @@ flowsRouter.delete(
 );
 
 /**
- * Regenerate the most recent generation in a flow
+ * Regenerate the most recent generation in a flow (Section 3.6)
  *
- * Identifies the latest generation in the flow and regenerates it:
- * - Uses exact same parameters (prompt, aspect ratio, references)
- * - Replaces existing output image (preserves ID and URLs)
- * - Returns error if flow has no generations
- * - Ordered by creation date (newest first)
+ * Logic:
+ * 1. Find the flow by ID
+ * 2. Query for the most recent generation (ordered by createdAt desc)
+ * 3. Trigger regeneration with exact same parameters
+ * 4. Replace existing output image (preserves ID and URLs)
  *
  * @route POST /api/v1/flows/:id/regenerate
  * @authentication Project Key required
  * @rateLimit 100 requests per hour per API key
  *
- * @param {string} req.params.id - Flow ID (UUID)
+ * @param {string} req.params.id - Flow ID (affects: determines which flow's latest generation to regenerate)
  *
- * @returns {object} 200 - Regenerated generation response
+ * @returns {object} 200 - Regenerated generation with updated output image
  * @returns {object} 404 - Flow not found or access denied
  * @returns {object} 400 - Flow has no generations
  * @returns {object} 401 - Missing or invalid API key
  * @returns {object} 429 - Rate limit exceeded
  *
  * @throws {Error} FLOW_NOT_FOUND - Flow does not exist
- * @throws {Error} FLOW_HAS_NO_GENERATIONS - Flow contains no generations
+ * @throws {Error} FLOW_HAS_NO_GENERATIONS - Flow contains no generations to regenerate
  *
  * @example
  * POST /api/v1/flows/550e8400-e29b-41d4-a716-446655440000/regenerate
@@ -558,15 +558,16 @@ flowsRouter.post(
 );
 
 /**
- * Delete a flow (hard delete)
+ * Delete a flow with cascade deletion (Section 7.3)
  *
- * Permanently removes the flow record:
- * - Flow record is hard deleted (no soft delete)
- * - Generations remain intact (not cascaded)
- * - Images remain intact (not cascaded)
- * - Flow-scoped aliases are removed with flow
+ * Permanently removes the flow with cascade behavior:
+ * - Flow record is hard deleted
+ * - All generations in flow are hard deleted
+ * - Images WITHOUT project alias: hard deleted with MinIO cleanup
+ * - Images WITH project alias: kept, but flowId set to NULL (unlinked)
  *
- * Note: Generations and images lose their flow association but remain accessible.
+ * Rationale: Images with project aliases are used globally and should be preserved.
+ * Flow deletion removes the organizational structure but protects important assets.
  *
  * @route DELETE /api/v1/flows/:id
  * @authentication Project Key required
diff --git a/apps/api-service/src/routes/v1/generations.ts b/apps/api-service/src/routes/v1/generations.ts
index 9b4e4cb..f7cd5d6 100644
--- a/apps/api-service/src/routes/v1/generations.ts
+++ b/apps/api-service/src/routes/v1/generations.ts
@@ -478,13 +478,15 @@ generationsRouter.post(
 );
 
 /**
- * Delete a generation and its output image
+ * Delete a generation and conditionally its output image (Section 7.2)
  *
  * Performs deletion with alias protection:
- * - Soft delete generation record (sets deletedAt timestamp)
- * - Hard delete output image if no project/flow aliases exist
- * - Soft delete output image if aliases exist (preserves for CDN access)
- * - Cascades to remove generation-image relationships
+ * - Hard delete generation record (permanently removed from database)
+ * - If output image has NO project alias: hard delete image with MinIO cleanup
+ * - If output image HAS project alias: keep image, set generationId=NULL
+ *
+ * Rationale: Images with aliases are used as standalone assets and should be preserved.
+ * Images without aliases were created only for this generation and can be deleted together.
  *
  * @route DELETE /api/v1/generations/:id
  * @authentication Project Key required
diff --git a/apps/api-service/src/services/core/AliasService.ts b/apps/api-service/src/services/core/AliasService.ts
index ff842ef..4141b0e 100644
--- a/apps/api-service/src/services/core/AliasService.ts
+++ b/apps/api-service/src/services/core/AliasService.ts
@@ -1,4 +1,4 @@
-import { eq, and, isNull, desc } from 'drizzle-orm';
+import { eq, and, isNull, desc, or } from 'drizzle-orm';
 import { db } from '@/db';
 import { images, flows } from '@banatie/database';
 import type { AliasResolution, Image } from '@/types/models';
@@ -142,9 +142,11 @@ export class AliasService {
     flowId: string,
     projectId: string
   ): Promise<Image | undefined> {
+    // Check both flowId and pendingFlowId to support lazy flow pattern (Section 4.1)
+    // Images may have pendingFlowId before the flow record is created
     return await db.query.images.findFirst({
       where: and(
-        eq(images.flowId, flowId),
+        or(eq(images.flowId, flowId), eq(images.pendingFlowId, flowId)),
         eq(images.projectId, projectId),
         eq(images.source, 'generated'),
         isNull(images.deletedAt)
@@ -157,9 +159,10 @@ export class AliasService {
     flowId: string,
     projectId: string
   ): Promise<Image | undefined> {
+    // Check both flowId and pendingFlowId to support lazy flow pattern (Section 4.1)
     const allImages = await db.query.images.findMany({
       where: and(
-        eq(images.flowId, flowId),
+        or(eq(images.flowId, flowId), eq(images.pendingFlowId, flowId)),
         eq(images.projectId, projectId),
         eq(images.source, 'generated'),
         isNull(images.deletedAt)
@@ -175,9 +178,10 @@ export class AliasService {
     flowId: string,
     projectId: string
   ): Promise<Image | undefined> {
+    // Check both flowId and pendingFlowId to support lazy flow pattern (Section 4.1)
     return await db.query.images.findFirst({
       where: and(
-        eq(images.flowId, flowId),
+        or(eq(images.flowId, flowId), eq(images.pendingFlowId, flowId)),
         eq(images.projectId, projectId),
         eq(images.source, 'uploaded'),
         isNull(images.deletedAt)
diff --git a/apps/api-service/src/services/core/ImageService.ts b/apps/api-service/src/services/core/ImageService.ts
index dfbe2c3..668fbfb 100644
--- a/apps/api-service/src/services/core/ImageService.ts
+++ b/apps/api-service/src/services/core/ImageService.ts
@@ -215,17 +215,10 @@ export class ImageService {
       await db.delete(images).where(eq(images.id, id));
 
     } catch (error) {
-      // If MinIO delete fails, still proceed with DB cleanup (MVP mindset)
-      // Log error but don't throw
-      console.error('MinIO delete failed, proceeding with DB cleanup:', error);
-
-      // Still perform DB cleanup
-      await db
-        .update(generations)
-        .set({ outputImageId: null })
-        .where(eq(generations.outputImageId, id));
-
-      await db.delete(images).where(eq(images.id, id));
+      // Per Section 7.4: If MinIO delete fails, do NOT proceed with DB cleanup
+      // This prevents orphaned files in MinIO
+      console.error('MinIO delete failed, aborting image deletion:', error);
+      throw new Error(ERROR_MESSAGES.STORAGE_DELETE_FAILED || 'Failed to delete file from storage');
     }
   }
 
diff --git a/apps/api-service/src/types/responses.ts b/apps/api-service/src/types/responses.ts
index ed1034d..6082c45 100644
--- a/apps/api-service/src/types/responses.ts
+++ b/apps/api-service/src/types/responses.ts
@@ -268,7 +268,7 @@ export const toGenerationResponse = (gen: GenerationWithRelations): GenerationRe
 export const toImageResponse = (img: Image): ImageResponse => ({
   id: img.id,
   projectId: img.projectId,
-  flowId: img.flowId,
+  flowId: img.flowId ?? img.pendingFlowId ?? null, // Return actual flowId or pendingFlowId for client
   storageKey: img.storageKey,
   storageUrl: img.storageUrl,
   mimeType: img.mimeType,