Fix New session issues and websocket issues (#738)

* fix: reset-state-on-new-session-click

* fix(chat): preserve continuity while session ids settle

New conversations were crossing a short but important consistency gap.
The route could already point at a newly created session id while the
projects payload had not refreshed yet, and realtime/optimistic messages
could still be keyed under a provisional id. In that window the UI could
stop reading the active session store, briefly render the conversation as
missing, and then repopulate it a moment later.

That same gap also made duplication more likely. Optimistic local user
messages could survive long enough to appear beside the persisted copy,
and finalized assistant streaming rows could sit directly next to the
server-backed assistant message with the same content before realtime state
was cleared. The result was a chat view that felt unstable exactly when a
new session was being created.

This commit makes session-id reconciliation a first-class part of the chat
flow instead of assuming every layer will agree immediately. The session
store now understands canonical session aliases and can migrate one
conversation from a provisional id to the real id without dropping its
in-memory state. The route navigation path can replace the provisional URL
entry instead of stacking it in history, and the project/session selection
logic keeps a synthetic selected session alive long enough for the sidebar
and project payloads to catch up.

The practical goal is to keep one visible conversation throughout the whole
creation lifecycle: no dead window between websocket events and project
refresh, no stale provisional URL after the real id is known, and no extra
optimistic/local bubbles when server history catches up.

* fix(cli): resolve executable path for Claude CLI on Windows

* fix(session-synchronizer): improve session name extraction for Claude and Codex

server/shared/claude-cli-path.test.ts

@@ -0,0 +1,47 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import {
+  resolveClaudeCodeExecutablePath,
+  type ResolveClaudeCodeExecutablePathDependencies,
+} from '@/shared/claude-cli-path.js';
+
+test('resolveClaudeCodeExecutablePath resolves the npm Claude wrapper to its native exe on Windows', () => {
+  const wrapperDir = 'C:\\nvm4w\\nodejs';
+  const nativePath = `${wrapperDir}\\node_modules\\@anthropic-ai\\claude-code\\bin\\claude.exe`;
+  const execFileSync =
+    (() => `${wrapperDir}\\claude\r\n${wrapperDir}\\claude.cmd\r\n`) as unknown as ResolveClaudeCodeExecutablePathDependencies['execFileSync'];
+  const readFileSync = (() => '') as unknown as ResolveClaudeCodeExecutablePathDependencies['readFileSync'];
+
+  const resolved = resolveClaudeCodeExecutablePath('claude', {
+    platform: 'win32',
+    execFileSync,
+    existsSync: (candidate) => candidate === nativePath,
+    readFileSync,
+  });
+
+  assert.equal(resolved, nativePath);
+});
+
+test('resolveClaudeCodeExecutablePath keeps an explicit JavaScript launcher path unchanged', () => {
+  const scriptPath = 'C:\\tools\\claude.js';
+
+  const resolved = resolveClaudeCodeExecutablePath(scriptPath, {
+    platform: 'win32',
+  });
+
+  assert.equal(resolved, scriptPath);
+});
+
+test('resolveClaudeCodeExecutablePath falls back to the configured command when PATH lookup fails', () => {
+  const execFileSync = (() => {
+    throw new Error('not found');
+  }) as unknown as ResolveClaudeCodeExecutablePathDependencies['execFileSync'];
+
+  const resolved = resolveClaudeCodeExecutablePath('claude', {
+    platform: 'win32',
+    execFileSync,
+  });
+
+  assert.equal(resolved, 'claude');
+});