split: deterministic-tests, obsidian-plugin, local-cli, test-client, frontend root

New deterministic-tests workspace: scripted multi-client harness against
a real server (~110 scenario tests, server-control, managed-websocket,
test-runner). Updates to existing workspaces: obsidian-plugin (settings,
cursors, plugin entrypoint), local-client-cli (args, cli, file-watcher,
node-filesystem, path-utils + tests), test-client (mock-agent/client,
cli, error tracker). Bumps frontend root package.json/lock and adds
eslint config tweaks.

frontend/deterministic-tests/src/tests/queue-reset-loses-coalesced-local-edit.test.ts

@@ -0,0 +1,36 @@
+import type { AssertableState } from "../utils/assertable-state";
+import type { TestDefinition } from "../test-definition";
+
+export const queueResetLosesCoalescedLocalEditTest: TestDefinition = {
+    description:
+        "Client 0 goes offline, both clients edit doc.md concurrently, " +
+        "then client 0 reconnects. Both edits must be preserved.",
+    clients: 2,
+    steps: [
+        { type: "create", client: 0, path: "doc.md", content: "original" },
+        { type: "enable-sync", client: 0 },
+        { type: "enable-sync", client: 1 },
+        { type: "barrier" },
+
+        { type: "disable-sync", client: 0 },
+
+        { type: "update", client: 1, path: "doc.md", content: "alpha bravo" },
+        { type: "sync", client: 1 },
+
+        { type: "update", client: 0, path: "doc.md", content: "charlie delta" },
+
+        { type: "enable-sync", client: 0 },
+        { type: "barrier" },
+
+        {
+            type: "assert-consistent",
+            verify: (s: AssertableState): void => {
+                s.assertFileCount(1).assertContains(
+                    "doc.md",
+                    "alpha",
+                    "charlie"
+                );
+            }
+        }
+    ]
+};