Merge remote-tracking branch 'origin/main' into arpeggio

Patch deltas on existing rows now swap just the affected element via
replaceWith() instead of tearing down and rebuilding the entire
transcript. Stops the visible flash and preserves text selection.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/catalog.ts

@@ -663,8 +663,9 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
     applyNav();
   };
 
-  // Hover previews the row under the pointer (docs/PREVIEW.md). Touch is left
-  // out: there is no hover there, and a tap already opens the session.
+  // Pointer hover previews only while Ctrl is held — plain hover was too
+  // disruptive when sweeping the sidebar. Keyboard walk (j/k) still previews
+  // unconditionally via applyNav.
   let hovered: string | null = null;
   const setHovered = (id: string | null) => {
     if (hovered === id) return;
@@ -672,7 +673,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
     opts.onPreview?.(id);
   };
   treeHost.addEventListener("pointerover", (e) => {
-    if (e.pointerType === "touch") return;
+    if (e.pointerType === "touch" || !e.ctrlKey) return;
     const row = (e.target as HTMLElement | null)?.closest<HTMLElement>(".tree-leaf");
     setHovered(row?.dataset.sessionId ?? null);
   });

web/src/sidebarNav.test.ts

@@ -182,26 +182,32 @@ describe("sidebar preview requests (docs/PREVIEW.md)", () => {
     expect(seen.at(-1)).toBe(null);
   });
 
-  it("asks for a preview of the hovered card, and clears it on the way out", () => {
+  it("ctrl+hover previews a card, plain hover does not", () => {
     const seen: (string | null)[] = [];
     const { el } = twoFolders({ onPreview: (id) => seen.push(id) });
     const card = el.querySelectorAll<HTMLElement>(".tree-leaf")[0];
 
+    // Plain hover — no preview.
     card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse" }));
+    expect(seen).toEqual([]);
+
+    // Ctrl+hover — preview fires.
+    card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse", ctrlKey: true }));
     expect(seen).toEqual([A]);
-    // Moving within the same card is not a new preview.
-    card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse" }));
+
+    // Deduplicated while still on the same card.
+    card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse", ctrlKey: true }));
     expect(seen).toHaveLength(1);
 
     tree(el).dispatchEvent(new PointerEvent("pointerleave", { pointerType: "mouse" }));
     expect(seen.at(-1)).toBe(null);
   });
 
-  it("ignores touch, where a tap already opens the session", () => {
+  it("ignores touch even with ctrl", () => {
     const seen: (string | null)[] = [];
     const { el } = twoFolders({ onPreview: (id) => seen.push(id) });
     const card = el.querySelectorAll<HTMLElement>(".tree-leaf")[0];
-    card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "touch" }));
+    card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "touch", ctrlKey: true }));
     expect(seen).toEqual([]);
   });
 });

web/src/spawnForm.ts

@@ -11,7 +11,7 @@ import { attachDirAutocomplete } from "./dirAutocomplete.js";
 import { parentDir } from "./paths.js";
 import { filterProjects, groupProjects, isStale, sortProjects } from "./projectList.js";
 import type { ProjectGroup } from "./projectList.js";
-import { splitCommand } from "./toolIcon.js";
+import { splitCommand, toolIconSvg, TOOL_LABELS } from "./toolIcon.js";
 import { abbreviateCwd } from "./types.js";
 import type { BranchInfo, CreateSessionRequest, Project, Session, SpawnPreset } from "./types.js";
 
@@ -140,6 +140,12 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   const form = document.createElement("form");
   form.className = "spawn-form";
   form.innerHTML = `
+    <div class="field">
+      <span class="field-label">Harness</span>
+      <div class="harness-grid cmd-tiles"></div>
+      <input class="raw-input cmd-raw" name="command_raw" type="text" hidden
+             placeholder="bash -l" autocomplete="off" />
+    </div>
     <div class="field">
       <span class="field-label">Project</span>
       <input class="raw-input project-filter" type="text" placeholder="Filter projects…"
@@ -151,12 +157,6 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
                placeholder="/home/user/project" inputmode="text" autocomplete="off" />
       </div>
     </div>
-    <div class="field">
-      <span class="field-label">Command</span>
-      <div class="tile-row cmd-tiles"></div>
-      <input class="raw-input cmd-raw" name="command_raw" type="text" hidden
-             placeholder="bash -l" autocomplete="off" />
-    </div>
     <div class="advanced">
       <button type="button" class="tree-folder-header wt-toggle" aria-expanded="false">
         <span class="chevron">▾</span>
@@ -348,37 +348,69 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       command = preset!.command;
     }
     updateStructuredAvailability();
-    for (const tile of cmdTiles.querySelectorAll(".tile")) {
-      tile.classList.toggle("is-active", (tile as HTMLElement).dataset.id === id);
+    for (const card of cmdTiles.querySelectorAll(".harness-card")) {
+      card.classList.toggle("is-active", (card as HTMLElement).dataset.id === id);
     }
     emit();
   }
 
-  /** Re-highlight the operator's already-picked tile after `renderCommandTiles`
-   * rebuilds the row from scratch (new tiles carry no `is-active` class) —
+  /** Re-highlight the operator's already-picked card after `renderCommandTiles`
+   * rebuilds the grid from scratch (new cards carry no `is-active` class) —
    * without touching `command`, since that was already settled. */
   function reapplyActiveTile(): void {
-    for (const tile of cmdTiles.querySelectorAll(".tile")) {
-      tile.classList.toggle("is-active", (tile as HTMLElement).dataset.id === selectedPresetId);
+    for (const card of cmdTiles.querySelectorAll(".harness-card")) {
+      card.classList.toggle("is-active", (card as HTMLElement).dataset.id === selectedPresetId);
     }
   }
 
+  /** Resolve a preset id to a tool icon id. The preset's command is the
+   * source of truth — `splitCommand` extracts the tool the same way the
+   * sidebar does. For the "Custom…" preset (empty command) there is no
+   * tool to show, and a terminal prompt stands in. */
+  function presetToolId(p: SpawnPreset): string | null {
+    if (!p.command) return null;
+    return splitCommand(p.command).tool;
+  }
+
   function renderCommandTiles(): void {
     cmdTiles.replaceChildren();
     for (const p of presets) {
-      const tile = document.createElement("button");
-      tile.type = "button";
-      tile.className = "tile";
-      tile.dataset.id = p.id;
-      tile.innerHTML = `<span class="tile-label">${escapeHtml(p.label)}</span>`;
-      tile.addEventListener("click", () => {
+      const isCustom = p.command === "";
+      const card = document.createElement("button");
+      card.type = "button";
+      card.className = isCustom ? "harness-card harness-custom" : "harness-card";
+      card.dataset.id = p.id;
+      const toolId = presetToolId(p);
+      const iconHtml = isCustom ? customIcon() : toolId ? harnessIcon(toolId) : harnessIcon("shell");
+      const label = TOOL_LABELS[toolId ?? ""] ?? p.label;
+      card.innerHTML =
+        `<span class="harness-icon">${iconHtml}</span>` +
+        `<span class="harness-label">${escapeHtml(isCustom ? "Custom\u2026" : label)}</span>`;
+      card.addEventListener("click", () => {
         commandTouched = true;
         selectPreset(p.id);
       });
-      cmdTiles.appendChild(tile);
+      cmdTiles.appendChild(card);
     }
   }
 
+  /** Render a harness card icon at card size (24x24). Re-uses the SVG bodies
+   * from toolIcon.ts but at a larger viewport so the marks breathe. */
+  function harnessIcon(toolId: string): string {
+    // toolIconSvg renders at 13x13 with viewBox 0 0 16 16 — we want the
+    // same shape at 24x24 for the card context.
+    const small = toolIconSvg(toolId);
+    if (!small) return "";
+    return small
+      .replace(/width="13"/g, 'width="24"')
+      .replace(/height="13"/g, 'height="24"');
+  }
+
+  /** An ellipsis mark for the "Custom…" escape hatch. */
+  function customIcon(): string {
+    return `<svg class="tool-icon" viewBox="0 0 16 16" width="24" height="24" role="img" aria-label="Custom command"><title>Custom command</title><g fill="currentColor"><circle cx="4" cy="8" r="1.3"/><circle cx="8" cy="8" r="1.3"/><circle cx="12" cy="8" r="1.3"/></g></svg>`;
+  }
+
   // Set once the operator picks a tile or types a custom command — guards
   // `applyInitialCommand()` the same way `nameTouched` guards a late name
   // batch: a late `/api/info` resolution must never overwrite a field the

web/src/spawnFormEnter.test.ts

@@ -139,7 +139,7 @@ describe("spawnForm Enter-to-submit (#97)", () => {
       const form = await mount([MAESTRO]);
       box(form, MAESTRO.path).click();
       await drain();
-      form.querySelector<HTMLButtonElement>('.cmd-tiles .tile[data-id="custom"]')!.click();
+      form.querySelector<HTMLButtonElement>('.cmd-tiles .harness-card[data-id="custom"]')!.click();
       const raw = form.querySelector<HTMLInputElement>(".cmd-raw")!;
       raw.value = "bash -l";
       raw.dispatchEvent(new Event("input"));

web/src/spawnFormPreset.test.ts

@@ -63,7 +63,7 @@ describe("spawnForm preset selection vs. late /api/info (#76)", () => {
     await drain();
 
     // Fallback presets are up; the operator picks "zsh" before /api/info lands.
-    const zshTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+    const zshTile = [...form.querySelectorAll<HTMLButtonElement>(".harness-card")].find(
       (t) => t.dataset.id === "zsh",
     )!;
     zshTile.click();
@@ -88,7 +88,7 @@ describe("spawnForm preset selection vs. late /api/info (#76)", () => {
     document.body.appendChild(form);
     await drain();
 
-    const customTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+    const customTile = [...form.querySelectorAll<HTMLButtonElement>(".harness-card")].find(
       (t) => t.dataset.id === "custom",
     )!;
     customTile.click();
@@ -116,7 +116,7 @@ describe("spawnForm preset selection vs. late /api/info (#76)", () => {
 
     // Untouched: the refined preset list is still free to settle the command.
     expect(values?.command).toBe("claude");
-    const fishTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+    const fishTile = [...form.querySelectorAll<HTMLButtonElement>(".harness-card")].find(
       (t) => t.dataset.id === "fish",
     );
     expect(fishTile).toBeDefined();

web/src/spawnModal.test.ts

@@ -52,14 +52,14 @@ describe("spawn modal", () => {
     expect(host.querySelector(".form-actions .cancel")).toBeTruthy();
   });
 
-  it("opens with the project filter focused, ahead of the command tiles", async () => {
+  it("opens with the project filter focused, harness before project", async () => {
     openSpawnModal({ onSuccess: () => {} });
     await flush();
 
     const form = modal()!.querySelector("form.spawn-form")!;
     expect(document.activeElement).toBe(form.querySelector(".project-filter"));
     const fields = [...form.querySelectorAll(".field .field-label")].map((el) => el.textContent);
-    expect(fields.slice(0, 2)).toEqual(["Project", "Command"]);
+    expect(fields.slice(0, 2)).toEqual(["Harness", "Project"]);
   });
 
   it("titles a seeded open as a clone", async () => {

web/src/structured.ts

@@ -551,6 +551,19 @@ export function createStructuredConnection(
           rows.push(delta.row);
         } else {
           rows[i] = delta.row;
+          // Surgical DOM swap: replace just this row's element instead of
+          // tearing down and rebuilding the entire transcript, which causes
+          // visible flashing and breaks text selection.
+          const oldEl = rowEls.get(delta.row.id);
+          if (oldEl) {
+            const newEl = buildRowElement(delta.row);
+            if (newEl) {
+              oldEl.replaceWith(newEl);
+              rowEls.set(delta.row.id, newEl);
+            }
+            syncAvailableCommands();
+            return;
+          }
         }
       } else {
         const i = rowIndex.get(delta.id);

web/src/styles.css

@@ -3651,61 +3651,78 @@ input.leaf-rename:focus {
   color: var(--ink);
 }
 
-/* One-click tiles: host row + command row. */
-.tile-row {
-  display: flex;
-  flex-wrap: wrap;
+/* Harness cards: the first decision in the spawn form — which tool runs. */
+.harness-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
   gap: var(--sp-2);
 }
 
-.tile {
-  flex: 1 1 auto;
-  min-width: 96px;
+.harness-card {
   display: flex;
   flex-direction: column;
-  gap: 2px;
-  align-items: flex-start;
-  padding: var(--sp-2) var(--sp-3);
+  align-items: center;
+  gap: var(--sp-2);
+  padding: var(--sp-3) var(--sp-2);
   background: var(--surface-2);
   border: 1px solid var(--border);
   border-radius: var(--r-2);
   color: var(--ink);
   font-family: inherit;
   cursor: pointer;
-  text-align: left;
+  text-align: center;
   transition:
     border-color var(--dur-fast) var(--ease-out),
     background var(--dur-fast) var(--ease-out);
 }
 
-.tile:hover {
+.harness-card:hover {
   border-color: var(--border-strong);
+  background: var(--surface-3);
 }
 
-.tile.is-active {
+.harness-card.is-active {
   border-color: var(--accent);
   background: var(--accent-tint);
 }
 
-.tile-label {
-  font-size: var(--fs-14);
-  font-weight: 600;
-}
-
-.tile-sub {
-  font-size: var(--fs-12);
-  color: var(--muted);
-  font-family: var(--font-mono);
-}
-
-.tile-more {
-  flex: 0 0 auto;
-  min-width: 0;
-  justify-content: center;
+.harness-icon {
+  display: flex;
   align-items: center;
+  justify-content: center;
+  width: 32px;
+  height: 32px;
   color: var(--muted);
 }
 
+.harness-card.is-active .harness-icon {
+  color: var(--ink);
+}
+
+.harness-icon .tool-icon {
+  display: block;
+}
+
+.harness-label {
+  font-size: var(--fs-13);
+  font-weight: 600;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 100%;
+}
+
+/* The "Custom…" card is an escape hatch, not a peer tool — dashed border
+   and subdued color separate it from the named harnesses. */
+.harness-custom {
+  border-style: dashed;
+  color: var(--muted);
+}
+
+.harness-custom .harness-label {
+  font-weight: 500;
+}
+
 /* Working-directory picker (#95). Two steps: a grid of project boxes, then the
    picked project's worktree choices. Stale beyond 7 days dims but stays
    selectable. */