fix(web): new session button fails on fresh start with no opened projects

On a fresh `opencode web` start, the "New Session" button in the titlebar
silently does nothing and the home page hides its "New Session" buttons.
This happens because:

1. `newSessionProject()` in home.tsx relies solely on
   `projects()` (persisted opened projects), which is empty.

2. `openNewTab()` in titlebar.tsx has a 5-case fallback chain that
   all fail when no projects are persisted: home selection is empty,
   layout.projects.list() is empty, and
   global.ensureServerCtx(conn).projects.list() returns only persisted
   projects — never server-registered ones.

Fix:
- home.tsx: add sync data fallback to `newSessionProject` (registered
  projects from the server API)
- titlebar.tsx: add a final fallback that reads server-registered
  projects from sync.data.project when all other cases fail

Author: sword

packages/app/src/components/titlebar.tsx

@@ -367,9 +367,21 @@ export function Titlebar(props: { update?: TitlebarUpdate }) {
                 const project = global.ensureServerCtx(conn).projects.list()[0]
                 return project ? [{ server: ServerConnection.key(conn), project }] : []
               })[0]
-              if (!fallback) return
+              if (fallback) {
+                tabs.newDraft({ server: fallback.server, directory: fallback.project.worktree }, "")
+                return
+              }
 
-              tabs.newDraft({ server: fallback.server, directory: fallback.project.worktree }, "")
+              // Last resort: use server-registered projects from sync data when
+              // no projects have been opened yet (fresh web start)
+              const conn = global.servers.list()[0] ?? server.current
+              if (conn) {
+                const ctx = global.ensureServerCtx(conn)
+                const registered = ctx.sync.data.project[0]
+                if (registered) {
+                  tabs.newDraft({ server: ServerConnection.key(conn), directory: registered.worktree }, "")
+                }
+              }
             }
             const toggleHome = () => tabs.toggleHome({ home: layout.route().type === "home", current: currentTab() })
 

packages/app/src/pages/home.tsx

@@ -332,7 +332,8 @@ export function NewHome() {
     () =>
       selectedProject() ??
       projects().find((project) => project.worktree === focusedServerCtx()?.projects.last()) ??
-      projects()[0],
+      projects()[0] ??
+      focusedSync().data.project[0] as LocalProject | undefined,
   )
   const directories = (project: LocalProject) => [project.worktree, ...(project.sandboxes ?? [])]
   const projectDirectories = createMemo(() => {