fix(project): stabilize project deletion

- Guard renderer project list/get against stale initial loads
- Retry project zip/cache removal to handle transient Windows locks
- Surface deletion failures in UI and add regression tests

Made-with: Cursor

app/renderer/editor/state/projectState.race.test.ts

@@ -0,0 +1,23 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
+import test from 'node:test';
+import { fileURLToPath } from 'node:url';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+
+void test('projectState: list/get after delete invalidates in-flight initial load (epoch guard)', () => {
+  const src = fs.readFileSync(path.join(here, 'projectState.ts'), 'utf8');
+  assert.match(src, /projectDataEpochRef/);
+  assert.match(src, /const epoch = projectDataEpochRef\.current/);
+  assert.match(src, /if \(projectDataEpochRef\.current !== epoch\) return/);
+  assert.match(
+    src,
+    /const deleteProject = async[\s\S]+?projectDataEpochRef\.current \+= 1[\s\S]+?await api\.invoke/,
+  );
+  assert.match(
+    src,
+    /const openProject = async[\s\S]+?projectDataEpochRef\.current \+= 1[\s\S]+?await api\.invoke/,
+  );
+  assert.match(src, /const refreshProjects = async \(\) => \{[\s\S]+?projectDataEpochRef\.current \+= 1/);
+});