feat: Implement GitHub issue validation endpoint and UI integration

- Added a new endpoint for validating GitHub issues using the Claude SDK.
- Introduced validation schema and logic to handle issue validation requests.
- Updated GitHub routes to include the new validation route.
- Enhanced the UI with a validation dialog and button to trigger issue validation.
- Mapped issue complexity to feature priority for better task management.
- Integrated validation results display in the UI, allowing users to convert validated issues into tasks.

libs/types/src/index.ts

@@ -81,3 +81,15 @@ export {
   THINKING_LEVEL_LABELS,
   getModelDisplayName,
 } from './model-display.js';
+
+// Issue validation types
+export type {
+  IssueValidationVerdict,
+  IssueValidationConfidence,
+  IssueComplexity,
+  IssueValidationInput,
+  IssueValidationRequest,
+  IssueValidationResult,
+  IssueValidationResponse,
+  IssueValidationErrorResponse,
+} from './issue-validation.js';

libs/types/src/issue-validation.ts

@@ -0,0 +1,78 @@
+/**
+ * Issue Validation Types
+ *
+ * Types for validating GitHub issues against the codebase using Claude SDK.
+ */
+
+/**
+ * Verdict from issue validation
+ */
+export type IssueValidationVerdict = 'valid' | 'invalid' | 'needs_clarification';
+
+/**
+ * Confidence level of the validation
+ */
+export type IssueValidationConfidence = 'high' | 'medium' | 'low';
+
+/**
+ * Complexity estimation for valid issues
+ */
+export type IssueComplexity = 'trivial' | 'simple' | 'moderate' | 'complex' | 'very_complex';
+
+/**
+ * Issue data for validation (without projectPath)
+ * Used by UI when calling the validation API
+ */
+export interface IssueValidationInput {
+  issueNumber: number;
+  issueTitle: string;
+  issueBody: string;
+  issueLabels?: string[];
+}
+
+/**
+ * Full request payload for issue validation endpoint
+ * Includes projectPath for server-side handling
+ */
+export interface IssueValidationRequest extends IssueValidationInput {
+  projectPath: string;
+}
+
+/**
+ * Result from Claude's issue validation analysis
+ */
+export interface IssueValidationResult {
+  /** Whether the issue is valid, invalid, or needs clarification */
+  verdict: IssueValidationVerdict;
+  /** How confident the AI is in its assessment */
+  confidence: IssueValidationConfidence;
+  /** Detailed explanation of the verdict */
+  reasoning: string;
+  /** For bug reports: whether the bug was confirmed in the codebase */
+  bugConfirmed?: boolean;
+  /** Files related to the issue found during analysis */
+  relatedFiles?: string[];
+  /** Suggested approach to fix or implement */
+  suggestedFix?: string;
+  /** Information that's missing and needed for validation (when verdict = needs_clarification) */
+  missingInfo?: string[];
+  /** Estimated effort to address the issue */
+  estimatedComplexity?: IssueComplexity;
+}
+
+/**
+ * Successful response from validate-issue endpoint
+ */
+export interface IssueValidationResponse {
+  success: true;
+  issueNumber: number;
+  validation: IssueValidationResult;
+}
+
+/**
+ * Error response from validate-issue endpoint
+ */
+export interface IssueValidationErrorResponse {
+  success: false;
+  error: string;
+}