fix(maestro): spawn similar preselects the cloned project

Spawn similar dropped the session's cwd into the free-text directory hatch,
so the project picker showed nothing selected. For a worktree session that
cwd was the daemon-made checkout, and the worktree toggle defaulted on, so
the clone asked for a worktree of a worktree.

It now seeds the picker: the cloned project's box selected, the same
worktree decision, base repo plus '+ new' when the source had a worktree.
A seeded path that matches no project falls back to the raw input showing
that path instead of an empty picker.

web/src/main.ts

@@ -15,6 +15,7 @@ import {
   resolveFastForward,
 } from "./fastForward.js";
 import { FALLBACK_PRESETS } from "./spawnForm.js";
+import { spawnSimilarSeed } from "./spawnSimilar.js";
 import { mountHud, type Hud } from "./hud.js";
 import { emptyLayout, type Layout, openSessions } from "./layout.js";
 import { createMultiView, type MultiView } from "./multiview.js";
@@ -265,8 +266,8 @@ function showMultiView(): void {
 }
 
 // Spawn affordances (#62): the header button, the sidebar's empty state, and
-// `?mock&spawn` all open a draft pane; "Spawn similar" seeds one with the
-// cloned session's dir + command.
+// `?mock&spawn` all open a draft pane; "Spawn similar" seeds one from the
+// cloned session (see spawnSimilar.ts).
 function requestOpenSpawn(): void {
   showMultiView();
   // A new tab, not a split of the pane you were reading (#100). "Spawn
@@ -279,7 +280,7 @@ document.addEventListener(OPEN_SPAWN_EVENT, () => requestOpenSpawn());
 document.addEventListener("catalog-spawn-similar", (ev) => {
   const s = (ev as CustomEvent<Session>).detail;
   showMultiView();
-  mv.openDraft({ cwd: s.cwd, command: s.command });
+  mv.openDraft(spawnSimilarSeed(s));
 });
 
 // Fast-forward spawn (#67): the draft pane's keystroke neighbour spawns

web/src/spawnForm.ts

@@ -589,7 +589,10 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
         cwd = seedCwd;
         cwdRaw.value = seedCwd;
         // Restoring must not touch the worktree toggle — the seed carries it.
-        if (!restoreSelection(seedCwd)) clearProjectSelection();
+        // A path no box matches (the project is gone, or the scan never saw
+        // it) falls back to the raw input showing that path: an empty picker
+        // with an invisible cwd reads as a form that lost the directory.
+        if (!restoreSelection(seedCwd)) showRawCwd(seedCwd, false);
       } else {
         showRawCwd(seedCwd, false);
       }

web/src/spawnSimilar.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, it } from "vitest";
+import { spawnSimilarSeed } from "./spawnSimilar.js";
+import type { Session } from "./types.js";
+
+function session(overrides: Partial<Session> = {}): Session {
+  return {
+    id: "s1",
+    cwd: "/repos/app",
+    command: "claude",
+    env: {},
+    metadata: {},
+    status: "Running",
+    created_at: "2026-01-01T00:00:00Z",
+    ...overrides,
+  } as Session;
+}
+
+describe("spawnSimilarSeed (#28)", () => {
+  it("seeds the project picker, not the free-text hatch", () => {
+    const seed = spawnSimilarSeed(session());
+    expect(seed.cwd).toBe("/repos/app");
+    expect(seed.command).toBe("claude");
+    expect(seed.cwdRawVisible).toBe(false);
+  });
+
+  it("keeps the worktree toggle off for a session that has no worktree", () => {
+    expect(spawnSimilarSeed(session()).worktreeEnabled).toBe(false);
+  });
+
+  it("clones a worktree session as a new worktree of its base repo", () => {
+    const seed = spawnSimilarSeed(
+      session({
+        cwd: "/repos/app-worktrees/feature",
+        worktree: { path: "/repos/app-worktrees/feature", base_repo: "/repos/app" },
+      }),
+    );
+    expect(seed.cwd).toBe("/repos/app");
+    expect(seed.worktreeEnabled).toBe(true);
+  });
+
+  it("never carries the cloned session's name", () => {
+    const seed = spawnSimilarSeed(session({ metadata: { name: "amber-falcon" } }));
+    expect(seed.name).toBeUndefined();
+  });
+});

web/src/spawnSimilar.ts

@@ -0,0 +1,30 @@
+// "Spawn similar" (#28): the seed a cloned session hands to a draft pane.
+// Pure — the caller owns opening the pane.
+
+import type { Draft } from "./layout.js";
+import type { Session } from "./types.js";
+
+/** Clone a session into draft values: same project, same command, same
+ *  worktree decision, fresh name.
+ *
+ *  A worktree session seeds its *base repository*, not the checkout the daemon
+ *  made for it: "similar" is another session of that project, and the daemon
+ *  never adopts an existing worktree (docs/WORKTREES.md), so seeding the
+ *  checkout would ask it to build a worktree out of a worktree. The picker
+ *  then lands on that repository's box with "+ new" active.
+ *
+ *  `cwdRawVisible: false` keeps the two-step project picker on screen with the
+ *  cloned project selected, instead of dropping the path into the free-text
+ *  escape hatch.
+ *
+ *  The name is left out on purpose: a clone is a new session and takes its own
+ *  generated handle. */
+export function spawnSimilarSeed(s: Session): Partial<Draft> {
+  const wt = s.worktree ?? null;
+  return {
+    command: s.command,
+    cwd: wt ? wt.base_repo : s.cwd,
+    worktreeEnabled: wt != null,
+    cwdRawVisible: false,
+  };
+}

web/src/worktreeStep.test.ts

@@ -240,4 +240,35 @@ describe("spawnForm worktree step (#95)", () => {
     expect(box(form, MAESTRO.path).classList.contains("is-active")).toBe(true);
     expect(toggle(form).checked).toBe(false);
   });
+
+  it("lands a 'spawn similar' seed on the cloned project with '+ new' active", async () => {
+    urls = stubFetch([MAESTRO, WT_A, WT_B]);
+    handle = createSpawnForm({
+      onSuccess() {},
+      seed: { cwd: MAESTRO.path, cwdRawVisible: false, worktreeEnabled: true },
+    });
+    document.body.appendChild(handle.el);
+    await drain();
+    const form = handle.el;
+
+    expect(box(form, MAESTRO.path).classList.contains("is-active")).toBe(true);
+    expect(activeChoice(form)!.dataset.kind).toBe("new");
+    expect(toggle(form).checked).toBe(true);
+    expect(form.querySelector<HTMLElement>(".cwd-raw-wrap")!.hidden).toBe(true);
+  });
+
+  it("falls back to the raw input when the seeded directory matches no project", async () => {
+    urls = stubFetch([MAESTRO, WT_A]);
+    handle = createSpawnForm({
+      onSuccess() {},
+      seed: { cwd: "/home/user/gone", cwdRawVisible: false, worktreeEnabled: false },
+    });
+    document.body.appendChild(handle.el);
+    await drain();
+    const form = handle.el;
+
+    const raw = form.querySelector<HTMLInputElement>(".cwd-raw")!;
+    expect(form.querySelector<HTMLElement>(".cwd-raw-wrap")!.hidden).toBe(false);
+    expect(raw.value).toBe("/home/user/gone");
+  });
 });