feat(ui): add project filter to issues list

Add a "Project" filter section to the issues filter popover, following the
same pattern as the existing Assignee and Labels filters. Issues can now
be filtered by one or more projects from the filter dropdown.

Closes #129

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

ui/src/pages/Issues.tsx

@@ -3,6 +3,7 @@ import { useSearchParams } from "@/lib/router";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
 import { issuesApi } from "../api/issues";
 import { agentsApi } from "../api/agents";
+import { projectsApi } from "../api/projects";
 import { heartbeatsApi } from "../api/heartbeats";
 import { useCompany } from "../context/CompanyContext";
 import { useBreadcrumbs } from "../context/BreadcrumbContext";
@@ -48,6 +49,12 @@ export function Issues() {
     enabled: !!selectedCompanyId,
   });
 
+  const { data: projects } = useQuery({
+    queryKey: queryKeys.projects.list(selectedCompanyId!),
+    queryFn: () => projectsApi.list(selectedCompanyId!),
+    enabled: !!selectedCompanyId,
+  });
+
   const { data: liveRuns } = useQuery({
     queryKey: queryKeys.liveRuns(selectedCompanyId!),
     queryFn: () => heartbeatsApi.liveRunsForCompany(selectedCompanyId!),
@@ -91,6 +98,7 @@ export function Issues() {
       isLoading={isLoading}
       error={error as Error | null}
       agents={agents}
+      projects={projects}
       liveIssueIds={liveIssueIds}
       viewStateKey="paperclip:issues-view"
       initialAssignees={searchParams.get("assignee") ? [searchParams.get("assignee")!] : undefined}