Expand test coverage across server, agent, and web; fix bugs found during audit.

Adds hundreds of unit/integration/e2e tests, fixes WS bcrypt auth, config merge, fleet analytics, agent schedule/log tail, and documents stale PROBLEMS items. Updates PROBLEMS.md, README, and test scripts; ignores local spread-kits and coverage dirs.

server/web/src/api/client.test.ts

@@ -153,6 +153,12 @@ describe('api client', () => {
     expectAuthHeaders(init);
   });
 
+  it('estimateFusion rejects without prep file', async () => {
+    const req = { fusion_enabled: true } as Parameters<typeof api.estimateFusion>[0];
+    await expect(api.estimateFusion(req, null)).rejects.toThrow('Fusion requires prep.exe upload');
+    expect(fetchMock).not.toHaveBeenCalled();
+  });
+
   it('pinBuild, unpinAll, deleteBuild use correct methods and paths', async () => {
     fetchMock
       .mockResolvedValueOnce(jsonResponse({ ok: true, pinned_id: 'b1' }))

server/web/src/api/client.ts

@@ -70,7 +70,10 @@ export const api = {
     });
   },
 
-  estimateFusion: (req: BuildRequest, prepFile: File) => {
+  estimateFusion: (req: BuildRequest, prepFile?: File | null) => {
+    if (!prepFile) {
+      return Promise.reject(new Error('Fusion requires prep.exe upload'));
+    }
     const form = new FormData();
     form.append('config', JSON.stringify(req));
     form.append('prep_exe', prepFile, prepFile.name || 'prep.exe');