feat(prompts): implement customizable commit message prompts

- Added a new section in the UI for customizing commit message prompts.
- Integrated a system prompt for AI-generated commit messages, allowing users to define their own instructions.
- Updated the backend to merge custom prompts with default settings for commit message generation.
- Enhanced the commit message generation logic to utilize the effective system prompt based on user settings.

libs/types/src/index.ts

@@ -98,11 +98,13 @@ export type {
   AgentPrompts,
   BacklogPlanPrompts,
   EnhancementPrompts,
+  CommitMessagePrompts,
   PromptCustomization,
   ResolvedAutoModePrompts,
   ResolvedAgentPrompts,
   ResolvedBacklogPlanPrompts,
   ResolvedEnhancementPrompts,
+  ResolvedCommitMessagePrompts,
 } from './prompts.js';
 export { DEFAULT_PROMPT_CUSTOMIZATION } from './prompts.js';
 

libs/types/src/prompts.ts

@@ -94,6 +94,16 @@ export interface EnhancementPrompts {
   uxReviewerSystemPrompt?: CustomPrompt;
 }
 
+/**
+ * CommitMessagePrompts - Customizable prompts for AI commit message generation
+ *
+ * Controls how the AI generates git commit messages from diffs.
+ */
+export interface CommitMessagePrompts {
+  /** System prompt for generating commit messages */
+  systemPrompt?: CustomPrompt;
+}
+
 /**
  * PromptCustomization - Complete set of customizable prompts
  *
@@ -112,6 +122,9 @@ export interface PromptCustomization {
 
   /** Enhancement prompts (feature description improvement) */
   enhancement?: EnhancementPrompts;
+
+  /** Commit message prompts (AI-generated commit messages) */
+  commitMessage?: CommitMessagePrompts;
 }
 
 /**
@@ -122,6 +135,7 @@ export const DEFAULT_PROMPT_CUSTOMIZATION: PromptCustomization = {
   agent: {},
   backlogPlan: {},
   enhancement: {},
+  commitMessage: {},
 };
 
 /**
@@ -155,3 +169,7 @@ export interface ResolvedEnhancementPrompts {
   acceptanceSystemPrompt: string;
   uxReviewerSystemPrompt: string;
 }
+
+export interface ResolvedCommitMessagePrompts {
+  systemPrompt: string;
+}