feat: integrate Jira configuration into Header and layout

- Added `JiraConfigProvider` to `layout.tsx` for server-side Jira configuration retrieval.
- Updated `Header.tsx` to conditionally display a link to the Jira dashboard with the project key if Jira is configured.
- Enhanced user experience by integrating Jira settings into the main application layout.

src/contexts/JiraConfigContext.tsx

@@ -0,0 +1,40 @@
+'use client';
+
+import React, { createContext, useContext } from 'react';
+import { JiraConfig } from '@/lib/types';
+
+interface JiraConfigContextType {
+  config: JiraConfig;
+  isConfigured: boolean;
+}
+
+const JiraConfigContext = createContext<JiraConfigContextType | undefined>(undefined);
+
+interface JiraConfigProviderProps {
+  children: React.ReactNode;
+  config: JiraConfig;
+}
+
+export function JiraConfigProvider({ children, config }: JiraConfigProviderProps) {
+  // Une config Jira est considérée comme valide si elle a les champs obligatoires
+  const isConfigured = Boolean(
+    config.baseUrl && 
+    config.email && 
+    config.apiToken && 
+    config.enabled
+  );
+
+  return (
+    <JiraConfigContext.Provider value={{ config, isConfigured }}>
+      {children}
+    </JiraConfigContext.Provider>
+  );
+}
+
+export function useJiraConfig() {
+  const context = useContext(JiraConfigContext);
+  if (context === undefined) {
+    throw new Error('useJiraConfig must be used within a JiraConfigProvider');
+  }
+  return context;
+}