fix(ui): pass sourceRepo to PR/issue context calls for fork workflows (#2090) (#2091)

Fixes GitHub PR/issue context endpoints returning 404 when working
from a fork because they resolved the repo from origin remote only.

- Pass sourceRepo: status?.repo ?? null to all prContext() calls in
  PullRequestSection.tsx (5 call sites)
- Pass sourceRepo: args.pr.sourceRepo ?? null / args.issue.sourceRepo
  ?? null to NewWorktreeDialog.tsx (3 call sites: prContext, issueGet,
  issueComments)
- Add status?.repo to dependency arrays to prevent stale closures

The prStatus endpoint already resolves the correct repo through the
fork network; this change wires it through to the downstream API calls.

Closes #2090

Co-authored-by: bashrusakh <bashrusakh@users.noreply.github.com>

packages/ui/src/components/session/NewWorktreeDialog.tsx

@@ -496,12 +496,12 @@ export function NewWorktreeDialog({
         return;
       }
 
-      const issueRes = await github.issueGet(projectDirectory, args.issue.number);
+      const issueRes = await github.issueGet(projectDirectory, args.issue.number, { sourceRepo: args.issue.sourceRepo ?? null });
       if (issueRes.connected === false || !issueRes.repo || !issueRes.issue) {
         throw new Error('Failed to load issue context');
       }
 
-      const commentsRes = await github.issueComments(projectDirectory, args.issue.number);
+      const commentsRes = await github.issueComments(projectDirectory, args.issue.number, { sourceRepo: args.issue.sourceRepo ?? null });
       if (commentsRes.connected === false) {
         throw new Error('Failed to load issue comments');
       }
@@ -542,6 +542,7 @@ export function NewWorktreeDialog({
       }
 
       const prContext = await github.prContext(projectDirectory, args.pr.number, {
+        sourceRepo: args.pr.sourceRepo ?? null,
         includeDiff: args.includeDiff,
         includeCheckDetails: false,
       });