fix(connection): fail the load on a trustedHosts entry that is not a bare authority

WHATWG parsing would quietly read a hostname out of harness.internal/path or
user@harness.internal, authorizing the typo's hostname; other typos would sit
silently ignored until requests 403. Refuse every URL part beyond host[:port]
at plugin load.

packages/client/connection/src/api-request-trust.ts

@@ -40,6 +40,21 @@ function parseAuthority(authority: string): URL | undefined {
   }
 }
 
+/**
+ * Assert one configured `trustedHosts` entry is a bare authority (`host` or
+ * `host:port`) and nothing else. WHATWG parsing would quietly read a hostname
+ * out of `harness.internal/path` or `user@harness.internal` — a typo must fail
+ * the load loudly instead of authorizing its hostname or being ignored until
+ * requests 403. The delimiter test refuses every URL part beyond the authority
+ * (path, backslash path, query, fragment, userinfo); IPv6 brackets use none of
+ * them.
+ * @param entry - the configured value, verbatim.
+ */
+export function assertTrustedAuthority(entry: string): void {
+  if (parseAuthority(entry) !== undefined && !/[/\\?#@]/.test(entry)) return
+  throw new Error(`client-connection: trustedHosts entry ${JSON.stringify(entry)} is not a bare host[:port] authority`)
+}
+
 /**
  * Whether the request authority matches a `trustedHosts` entry. An entry with
  * an explicit port matches that exact authority; a port-less entry matches the

packages/client/connection/src/index.ts

@@ -6,7 +6,7 @@ import type { WebRoute } from '@deepseek-ai/dsh-host-webserver'
 import { toFetchHandler } from '@deepseek-ai/dsh-host-apiproxy'
 import { API_PATH } from './api-path.ts'
 import { bridge } from './http-bridge.ts'
-import { isTrustedApiRequest } from './api-request-trust.ts'
+import { assertTrustedAuthority, isTrustedApiRequest } from './api-request-trust.ts'
 
 export { API_PATH } from './api-path.ts'
 
@@ -23,7 +23,8 @@ export interface ConnectionConfig {
    * port-less `host` matching any port. The /api trust fence refuses any
    * browser request whose Host is neither loopback nor listed here, so a
    * non-loopback (`0.0.0.0`) deployment must declare the names it is reached
-   * by (the dsh CLI derives the machine's LAN IP literals itself).
+   * by (the dsh CLI derives the machine's LAN IP literals itself). An entry
+   * that is not a bare authority fails the plugin load.
    */
   trustedHosts?: string[]
 }
@@ -42,6 +43,9 @@ export const Config: z<ConnectionConfig> = z.object({
 export function apply(ctx: Context, config?: ConnectionConfig): void {
   // The Loader resolves schema defaults; hand-built test contexts may pass none.
   const trustedHosts = config?.trustedHosts ?? []
+  // Config boundary: a malformed entry fails the load loudly here rather than
+  // silently authorizing its hostname prefix at request time.
+  for (const entry of trustedHosts) assertTrustedAuthority(entry)
   const apiHandler = toFetchHandler(ctx.apiProxy)
   const route: WebRoute = {
     kind: 'prefix',