fix(debugger): finish PHP Remote Debug: taken port, waiting state, Port field (#1639)

A taken port now says which port is in use instead of Node's EADDRINUSE text; a listening PHP Remote Debug session shows "Listening for Xdebug on port N" instead of "Running…"; clearing the only field of a debug-only remote type keeps the form and shows the field as required; php-debug leaves the generic Debug adapter list until it has a launch template (#1623).

Co-authored-by: DanielADK <[email protected]>

src/features/debugger/remote.ts

@@ -5,6 +5,7 @@
  * PHP Remote Debug is the exception: its php-debug listens and Xdebug connects to it.
  * Only Debug applies to them (`debugOnly`); they launch no process.
  */
+import { tx } from "@/platform/i18n";
 import type { LaunchConfig, RunConfig } from "@/platform/ipc";
 import { workflowSettings } from "@/platform/workflowSettings";
 import type { RunConfigTypeContribution, RunConfigTypeField } from "@/workbench/contributions";
@@ -383,6 +384,12 @@ export function remoteAttachConfig(rc: RunConfig, root: string): LaunchConfig |
   }
 }
 
+/** What a session of `rc` shows while nothing is suspended, when it waits for the debuggee to connect. */
+export function remoteWaitingNote(rc: Pick<RunConfig, "kind" | "params"> | undefined): string | null {
+  if (rc?.kind !== PHP_REMOTE) return null;
+  return tx`Listening for Xdebug on port ${portOf(rc.params ?? {}, 9003)}`;
+}
+
 /** What a Remote JVM Debug configuration attaches to (before the listen mode relay). */
 export function remoteJvmTarget(rc: RunConfig): { mode: JdwpMode; host: string; port: number; module: string } {
   const p = rc.params ?? {};