feat(maestro): live directory autocomplete in spawn form (NAP-329)

Adds api.listDir + a reusable dirAutocomplete widget (live dropdown,
Tab/Enter completion, /-drill-in, per-(daemon,dir) cache) wired onto the
cwd and worktree base-repo fields, with matching dropdown styling.

web/src/api.ts

@@ -1,4 +1,11 @@
-import type { ApiError, CreateSessionRequest, DaemonInfo, Session, Uuid } from "./types.js";
+import type {
+  ApiError,
+  CreateSessionRequest,
+  DaemonInfo,
+  DirListing,
+  Session,
+  Uuid,
+} from "./types.js";
 
 async function jsonOrError<T>(res: Response): Promise<T> {
   if (res.ok) {
@@ -43,6 +50,14 @@ export async function killSession(id: Uuid): Promise<void> {
   );
 }
 
+/** List one directory's immediate subdirectories on `daemonId`'s host (NAP-329).
+ * `path` may be empty, `~`, relative, or absolute — the daemon resolves it
+ * against its own home dir. */
+export async function listDir(daemonId: string, path: string): Promise<DirListing> {
+  const url = `/api/daemons/${encodeURIComponent(daemonId)}/dirs?path=${encodeURIComponent(path)}`;
+  return jsonOrError(await fetch(url, { credentials: "same-origin" }));
+}
+
 export function eventsWsUrl(): string {
   const proto = location.protocol === "https:" ? "wss:" : "ws:";
   return `${proto}//${location.host}/api/events`;

web/src/spawn.ts

@@ -1,4 +1,5 @@
 import { createSession } from "./api.js";
+import { attachDirAutocomplete } from "./dirAutocomplete.js";
 import type { CreateSessionRequest, DaemonInfo } from "./types.js";
 
 export function openSpawnModal(daemons: Map<string, DaemonInfo>): void {
@@ -97,7 +98,21 @@ export function openSpawnModal(daemons: Map<string, DaemonInfo>): void {
   select.addEventListener("change", applyHomeDir);
   applyHomeDir();
 
-  const close = () => host.remove();
+  // Live directory autocomplete (NAP-329) on the path fields, scoped to the
+  // currently-selected daemon — re-reading `select.value` per query means it
+  // tracks host changes for free.
+  const baseRepoInput = host.querySelector(
+    "input[name=worktree_base_repo]",
+  ) as HTMLInputElement;
+  const autocompletes = [
+    attachDirAutocomplete(cwdInput, () => select.value),
+    attachDirAutocomplete(baseRepoInput, () => select.value),
+  ];
+
+  const close = () => {
+    autocompletes.forEach((a) => a.destroy());
+    host.remove();
+  };
   host.querySelector(".close")?.addEventListener("click", close);
   host.querySelector(".cancel")?.addEventListener("click", close);
   host.addEventListener("click", (e) => {

web/src/styles.css

@@ -1052,6 +1052,52 @@ textarea {
   border-radius: var(--r-2);
 }
 
+/* ---------- directory autocomplete (NAP-329) ---------- */
+
+.dir-ac {
+  position: fixed;
+  z-index: var(--z-toast); /* above the modal it completes within */
+  margin: 0;
+  padding: var(--sp-1);
+  list-style: none;
+  max-height: 280px;
+  overflow-y: auto;
+  background: var(--surface);
+  border: 1px solid var(--border-strong);
+  border-radius: var(--r-2);
+  box-shadow: var(--shadow-2);
+  scrollbar-width: thin;
+  scrollbar-color: var(--border-strong) transparent;
+}
+
+.dir-ac-item {
+  padding: 6px var(--sp-2);
+  border-radius: var(--r-1);
+  color: var(--ink);
+  font-family: var(--font-mono);
+  font-size: var(--fs-14);
+  cursor: pointer;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.dir-ac-item:hover {
+  background: var(--surface-2);
+}
+
+.dir-ac-item.is-active {
+  background: var(--accent-tint);
+  color: var(--ink);
+}
+
+.dir-ac-more {
+  padding: 6px var(--sp-2);
+  color: var(--faint);
+  font-size: var(--fs-12);
+  font-style: italic;
+}
+
 /* ---------- not-found ---------- */
 
 .not-found {

web/src/types.ts

@@ -27,6 +27,16 @@ export interface DaemonInfo {
   home_dir?: string;
 }
 
+/** One directory's immediate subdirectories on a daemon's host (NAP-329). */
+export interface DirListing {
+  /** Resolved absolute directory that was listed (after ~/relative expansion). */
+  path: string;
+  /** Immediate subdirectory names, sorted case-insensitively. */
+  entries: string[];
+  /** True when the listing was capped server-side. */
+  truncated?: boolean;
+}
+
 export interface WorktreeSpec {
   base_repo: string;
   branch: string;