feat: add a runtime diagnostics page

Adds GET /api/clouds/:cloud/diagnostics and a Diagnostics page in the
General nav. The report combines, in one call:

- runtime reachability, latency, version and edition from /_floci/health
- every service the runtime emulates, with the console pages backed by it
- per-console-service probes (the existing status check)
- EC2 instance containers from /_floci/diagnose
- console uptime, sign-in mode and active session count

Each source is optional, so a down runtime still yields a partial report.

packages/api/src/routes/clouds.ts

@@ -14,6 +14,7 @@ import {isServiceType} from '../cloud-spi/serviceCatalog'
 import {mapAwsSdkError} from '../adapter-aws/awsErrors'
 import {serviceForAccount} from '../cloudProxy'
 import {CloudProxyService} from '../service/CloudProxyService'
+import {runtimeDiagnostics} from '../service/runtimeDiagnostics'
 import {deployLightsailNodeApplication, deployLightsailStaticFiles} from '../services/lightsailDeployment'
 
 // Header (and query-param fallback for direct links such as object downloads)
@@ -64,6 +65,12 @@ export function createCloudRoutes(injectedService?: CloudProxyService) {
         return c.json(await svc(c).status(cloud, {includeServices}))
     })
 
+    app.get('/:cloud/diagnostics', async (c) => {
+        const cloud = c.req.param('cloud') as CloudProvider
+        if (!isCloudProvider(cloud)) return c.json({error: 'Unknown cloud'}, 404)
+        return c.json(await runtimeDiagnostics(cloud, svc(c)))
+    })
+
     app.get('/:cloud/services/:service/status', async (c) => {
         const cloud = c.req.param('cloud') as CloudProvider
         const serviceType = c.req.param('service') as CloudServiceType