fix: keep command-line debug session-only

frontend/src/App.svelte

@@ -219,7 +219,7 @@
       const settings = await App.GetAppSettings();
       debug.log('[App] checkVault: GetAppSettings returned', settings);
       flog('checkVault: GetAppSettings returned');
-      if (settings?.debug) debug.enable();
+      if (settings?.debug) debug.enable({ persist: false });
 
       debug.log('[App] checkVault: calling GetVaultStatus...');
       vaultStatus = await App.GetVaultStatus() || { status: 'unknown', path: '', vaultId: '' };

frontend/src/lib/log/debug.js

@@ -127,9 +127,11 @@ export var debug = {
   log: log,
   logf: logf,
   isEnabled: function () { return ENABLED; },
-  enable: function () {
+  enable: function (options) {
     ENABLED = true;
+    if (!options || options.persist !== false) {
       try { localStorage.setItem('verstak-debug', 'true'); } catch (e) {}
+    }
   },
   disable: function () {
     ENABLED = false;

frontend/tests/debug-mode-test.mjs

@@ -0,0 +1,32 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
+import vm from 'node:vm';
+
+const source = fs.readFileSync(path.resolve('frontend/src/lib/log/debug.js'), 'utf8');
+const values = new Map();
+const localStorage = {
+  getItem(key) { return values.has(key) ? values.get(key) : null; },
+  setItem(key, value) { values.set(key, String(value)); },
+  removeItem(key) { values.delete(key); },
+};
+const context = vm.createContext({
+  console: { log() {} },
+  localStorage,
+  window: { location: { search: '' } },
+});
+const module = new vm.SourceTextModule(source, { context, identifier: 'debug.js' });
+await module.link(() => { throw new Error('debug.js must not import modules'); });
+await module.evaluate();
+
+const { debug } = module.namespace;
+debug.enable({ persist: false });
+
+assert.equal(debug.isEnabled(), true, 'session debug should enable diagnostics');
+assert.equal(
+  localStorage.getItem('verstak-debug'),
+  null,
+  'a --debug session must not make diagnostics persist into ordinary launches',
+);
+
+console.log('debug mode smoke passed');

scripts/test.sh

@@ -43,6 +43,10 @@ WAILS_BINDINGS_STATUS=0
 (cd "$ROOT" && node frontend/tests/wails-bindings-test.mjs) || WAILS_BINDINGS_STATUS=$?
 report "Wails notification bindings" "$WAILS_BINDINGS_STATUS"
 
+DEBUG_MODE_STATUS=0
+(cd "$ROOT" && node --experimental-vm-modules frontend/tests/debug-mode-test.mjs) || DEBUG_MODE_STATUS=$?
+report "session-only debug mode" "$DEBUG_MODE_STATUS"
+
 # ── Frontend tests ──
 echo "[frontend]"
 if ensure_npm_deps "$ROOT/frontend"; then