feat(app): GUI backlog — splitter, drag-reorder, fit, persist, modal focus

- LayoutEngine: fix splitter resize (track pointer 1:1 via delta-from-start)
  and add panel drag-to-reorder using raw pointer events with drop indicators
- TerminalView: auto-fit xterm to container via FitAddon + ResizeObserver
- App/TopBar: toggleable sidebar; persist sidebar/events collapse in
  localStorage; bell icon opens the activity log
- Wizard: new-workspace modal now grabs focus and handles keyboard
- deps: add @xterm/addon-fit

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/TerminalView.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef } from "react";
 import { Terminal } from "@xterm/xterm";
 import { WebglAddon } from "@xterm/addon-webgl";
 import { SearchAddon } from "@xterm/addon-search";
+import { FitAddon } from "@xterm/addon-fit";
 import { attachSurface, detachSurface, sendInput, resizeSurface } from "./socketBridge";
 import { registerSearch, unregisterSearch } from "./searchRegistry";
 
@@ -25,6 +26,27 @@ export function TerminalView({ surfaceId }: { surfaceId: string }) {
     term.loadAddon(search);
     registerSearch(surfaceId, search);
 
+    const fit = new FitAddon();
+    term.loadAddon(fit);
+
+    // Fit the grid to the container and tell the daemon the new size. Coalesced
+    // through rAF so a burst of resize callbacks yields one resize per frame.
+    let rafId = 0;
+    let lastCols = 0, lastRows = 0;
+    const doFit = () => {
+      rafId = 0;
+      try { fit.fit(); } catch { return; }
+      if (term.cols !== lastCols || term.rows !== lastRows) {
+        lastCols = term.cols;
+        lastRows = term.rows;
+        void resizeSurface(surfaceId, term.cols, term.rows);
+      }
+    };
+    const scheduleFit = () => { if (!rafId) rafId = requestAnimationFrame(doFit); };
+
+    const ro = new ResizeObserver(scheduleFit);
+    ro.observe(ref.current);
+
     // Input → daemon.
     const inputDisposable = term.onData((data) => {
       void sendInput(surfaceId, encoder.encode(data));
@@ -38,14 +60,15 @@ export function TerminalView({ surfaceId }: { surfaceId: string }) {
     }).then((res) => {
       if (disposed) return;
       if (res.snapshot) term.write(res.snapshot);
-      if (res.cols && res.rows) {
-        term.resize(res.cols, res.rows);
-        void resizeSurface(surfaceId, res.cols, res.rows);
-      }
+      // Fit to the actual container rather than the daemon's stored geometry,
+      // then push the resulting size back so the PTY reflows to match.
+      scheduleFit();
     });
 
     return () => {
       disposed = true;
+      if (rafId) cancelAnimationFrame(rafId);
+      ro.disconnect();
       inputDisposable.dispose();
       void detachSurface(surfaceId);
       unregisterSearch(surfaceId);