revert: Keep CF project for session-tracking Jira issues

CU is a separate project. Session tracking stays in CF.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/services/jira.ts

@@ -81,7 +81,7 @@ export async function createSessionIssue(params: {
       method: 'POST',
       body: JSON.stringify({
         fields: {
-          project: { key: 'CU' },
+          project: { key: 'CF' },
           summary,
           description: {
             type: 'doc',