feat: per-request tracing via BSB createTrace

Each HTTP request gets a fresh BSB trace (not a child span of init).
onRequest creates trace, stores on event.context.obs. onError logs
with trace context. onResponse ends the trace. 4xx logged as warn,
5xx as error. H3EventContext typed with obs field.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/plugins/service-admin-http/index.ts

@@ -195,16 +195,37 @@ export class Plugin extends BSBService<InstanceType<typeof Config>, typeof Event
       otaImportApiKey: this.config.otaImportApiKey || undefined,
     };
 
+    const self = this;
     const app = new H3({
+      onRequest: (event) => {
+        const method = event.req.method ?? "GET";
+        const path = event.req.url ?? "/";
+        event.context.obs = self.createTrace(`${method} ${path}`, {
+          "http.method": method,
+          "http.url": path,
+        });
+      },
       onError: (error, event) => {
+        const reqObs = event.context.obs ?? obs;
         const status = error.status ?? 500;
         const path = event.req.url ?? "unknown";
         if (status >= 500) {
-          obs.log.warn("HTTP {status} {path}: {err}", {
+          reqObs.log.error("HTTP {status} {path}: {err}", {
             status,
             path,
             err: error.message ?? String(error),
           });
+        } else if (status >= 400) {
+          reqObs.log.warn("HTTP {status} {path}: {err}", {
+            status,
+            path,
+            err: error.message ?? String(error),
+          });
+        }
+      },
+      onResponse: (_response, event) => {
+        if (event.context.obs) {
+          event.context.obs.end();
         }
       },
     });

server/src/plugins/service-admin-http/middleware.ts

@@ -16,6 +16,7 @@ declare module "h3" {
     user?: User;
     session?: Session;
     apiKeyPrefix?: string;
+    obs?: import("@bsb/base").Observable;
   }
 }
 

server/src/plugins/service-api-http/index.ts

@@ -164,16 +164,37 @@ export class Plugin extends BSBService<InstanceType<typeof Config>, typeof Event
       },
     );
 
+    const self = this;
     const app = new H3({
+      onRequest: (event) => {
+        const method = event.req.method ?? "GET";
+        const path = event.req.url ?? "/";
+        event.context.obs = self.createTrace(`${method} ${path}`, {
+          "http.method": method,
+          "http.url": path,
+        });
+      },
       onError: (error, event) => {
+        const reqObs = event.context.obs ?? obs;
         const status = error.status ?? 500;
         const path = event.req.url ?? "unknown";
         if (status >= 500) {
-          obs.log.warn("HTTP {status} {path}: {err}", {
+          reqObs.log.error("HTTP {status} {path}: {err}", {
             status,
             path,
             err: error.message ?? String(error),
           });
+        } else if (status >= 400) {
+          reqObs.log.warn("HTTP {status} {path}: {err}", {
+            status,
+            path,
+            err: error.message ?? String(error),
+          });
+        }
+      },
+      onResponse: (_response, event) => {
+        if (event.context.obs) {
+          event.context.obs.end();
         }
       },
     });