fix(desktop): show git-described version in dev instead of stale 0.1.0

Packaged builds are unaffected: scripts/package.mjs already injects the
git tag into electron-builder's extraMetadata.version, so the .app users
download from GitHub Release reports the right version through
app.getVersion() and the auto-updater's latest.yml comparison works
correctly.

Dev mode (`pnpm dev:desktop`) didn't go through that path though, so
app.getVersion() returned the static "0.1.0" from package.json — the
new Settings → Updates panel surfaced this and made it look like the
dev build was ancient. Add a tiny getAppVersion() helper that falls
back to `git describe --tags --always --dirty` only when !app.isPackaged,
and use it for the app-info IPC. No change to packaged behavior; if git
is unavailable for any reason, we silently fall back to app.getVersion().

packages/views/issues/components/issue-detail.tsx

@@ -506,6 +506,9 @@ export function IssueDetail({ issueId, onDelete, defaultSidebarOpen = true, layo
                 <ChevronRight className="h-3 w-3 text-muted-foreground/50 shrink-0" />
               </>
             )}
+            <span className="shrink-0 text-muted-foreground">
+              {issue.identifier}
+            </span>
             <span className="truncate font-medium text-foreground">
               {issue.title}
             </span>