test: strengthen Cypress e2e tests with real API assertions

- Remove blanket uncaught:exception suppressor (API-only tests)
- Trim smoke test to single infra-verification assertion
- Rewrite health test with strict status/field assertions, no failOnStatusCode
- Add session CRUD tests (create, get, list, delete, 404 cases, cleanup)
- Use Cypress.env('API_URL') instead of baseUrl to avoid blocking smoke tests
- Remove unused main and type fields from package.json

cypress/e2e/smoke.cy.js

@@ -1,58 +1,7 @@
 /// <reference types="cypress" />
 
-/**
- * Smoke test to verify that the Cypress test infrastructure is
- * correctly installed and configured. These tests do NOT require
- * the lovdata-chat stack to be running.
- */
 describe('Cypress Infrastructure Smoke Test', () => {
     it('should execute a basic assertion', () => {
         expect(true).to.be.true;
     });
-
-    it('should handle arrays and objects', () => {
-        const session = {
-            id: 'test-session-001',
-            status: 'running',
-            model: 'opencode/kimi-k2.5-free',
-        };
-
-        expect(session).to.have.property('id');
-        expect(session.status).to.eq('running');
-        expect(session.model).to.include('kimi');
-    });
-
-    it('should validate the allowed models whitelist structure', () => {
-        const allowedModels = [
-            {
-                id: 'opencode/kimi-k2.5-free',
-                display_name: 'Kimi K2.5',
-                provider: 'zen',
-                is_reasoning: false,
-                is_default: true,
-            },
-            {
-                id: 'anthropic/claude-sonnet-4-thinking',
-                display_name: 'Claude Sonnet 4 (Thinking)',
-                provider: 'zen',
-                is_reasoning: true,
-                thinking_budget_default: 10000,
-                thinking_budget_max: 50000,
-            },
-        ];
-
-        expect(allowedModels).to.have.length(2);
-
-        const defaultModel = allowedModels.find((m) => m.is_default);
-        expect(defaultModel).to.exist;
-        expect(defaultModel.id).to.eq('opencode/kimi-k2.5-free');
-
-        const reasoningModels = allowedModels.filter((m) => m.is_reasoning);
-        expect(reasoningModels).to.have.length(1);
-        expect(reasoningModels[0]).to.have.property('thinking_budget_default');
-        expect(reasoningModels[0]).to.have.property('thinking_budget_max');
-        expect(reasoningModels[0].thinking_budget_max).to.be.greaterThan(
-            reasoningModels[0].thinking_budget_default
-        );
-    });
 });