canvas-frontend/src/App.tsx

// App shell — scene switcher + top bar + command palette + console + toaster.
import { useEffect } from "react";
import { useApp, scenarioById } from "./state/store";
import Landing from "./scenes/Landing";
import MissionControl from "./scenes/MissionControl";
import RunHistory from "./scenes/RunHistory";
import Studio from "./scenes/Studio";
import Settings from "./scenes/Settings";
import CommandBar from "./components/CommandBar";
import Toaster from "./components/Toaster";
import Console from "./components/Console";
import { Cmd, Home, Layers, History as HistoryIcon, Pulse, Refresh, Branch, Cog, User } from "./components/icons";
import { liveMeta } from "./data/scenarios";

export default function App() {
  const scene = useApp((s) => s.scene);
  const setScene = useApp((s) => s.setScene);
  const setCmdOpen = useApp((s) => s.setCmdOpen);
  const scenarioId = useApp((s) => s.scenarioId);
  const sc = scenarioById(scenarioId);
  const mode = useApp((s) => s.mode);
  const setMode = useApp((s) => s.setMode);
  const refreshLive = useApp((s) => s.refreshLive);
  const liveLoading = useApp((s) => s.liveLoading);
  const liveFetchedAt = useApp((s) => s.liveFetchedAt);
  const consoleOpen = useApp((s) => s.consoleOpen);
  const setConsoleOpen = useApp((s) => s.setConsoleOpen);
  const apiLogCount = useApp((s) => s.apiLog.length);
  const actor = useApp((s) => s.actor);
  const userEmail = useApp((s) => s.userEmail);
  const startPolling = useApp((s) => s.startPolling);
  const stopPolling = useApp((s) => s.stopPolling);

  useEffect(() => {
    if (mode === "live") startPolling();
    return () => stopPolling();
  }, [mode, startPolling, stopPolling]);

  const liveAge = liveFetchedAt ? `${Math.max(0, Math.floor((Date.now() - liveFetchedAt) / 1000))}s ago` : null;

  return (
    <div className={`shell shell-${scene}`}>
      {scene !== "landing" && (
        <header className="topbar" data-anchor="topbar">
          <button className="brand-lock brand-btn" onClick={() => setScene("landing")} aria-label="Home">
            <span className="brand-mark sm" />
            <span className="brand-name">FlowMaster</span>
            <span className="brand-divider" />
            <span className="brand-sub">Mission Control</span>
          </button>

          <nav className="tabs" role="tablist">
            <button role="tab" aria-selected={scene === "mission"} className={`tab${scene === "mission" ? " tab-sel" : ""}`} onClick={() => setScene("mission")}>
              <Layers size={13} /> Mission
            </button>
            <button role="tab" aria-selected={scene === "history"} className={`tab${scene === "history" ? " tab-sel" : ""}`} onClick={() => setScene("history")}>
              <HistoryIcon size={13} /> Runs
            </button>
            <button role="tab" aria-selected={scene === "studio"} className={`tab${scene === "studio" ? " tab-sel" : ""}`} onClick={() => setScene("studio")}>
              <Branch size={13} /> Studio
            </button>
            <button role="tab" aria-selected={scene === "settings"} className={`tab${scene === "settings" ? " tab-sel" : ""}`} onClick={() => setScene("settings")}>
              <Cog size={13} /> Settings
            </button>
            <button role="tab" aria-selected={false} className="tab" onClick={() => setScene("landing")}>
              <Home size={13} /> Home
            </button>
          </nav>

          <div className="topbar-mid">
            {sc && scene === "mission" && (
              <div className="topbar-context">
                <span className="topbar-chip">
                  <span className="dot dot-running" /> {sc.family.label}
                </span>
                <span className="topbar-chip">
                  <span className="mono">{sc.defName.slice(0, 40)}</span>
                </span>
                <span className="topbar-chip mono">{sc.version}</span>
                {sc.live ? (
                  <span className="tag tag-live">live · {liveMeta.fetchedFrom?.replace("https://", "")}</span>
                ) : (
                  <span className="tag tag-syn">blueprint</span>
                )}
              </div>
            )}
          </div>

          <div className="topbar-actions">
            <button
              className="link-btn user-btn"
              onClick={() => setScene("settings")}
              title={`Signed in as ${userEmail}${actor?.user_id ? ` (${actor.user_id.slice(0, 8)})` : ""}`}
            >
              <User size={12} />
              <span className="user-email">{userEmail.split("@")[0]}</span>
            </button>

            <button
              className={`link-btn mode-toggle mode-${mode}`}
              onClick={() => setMode(mode === "live" ? "snapshot" : "live")}
              disabled={liveLoading}
              title={mode === "live"
                ? `Live mode is on. Fetched ${liveAge}. Click to drop back to snapshot.`
                : "Click to fetch live scenarios from demo.flow-master.ai in the browser."}
            >
              {liveLoading ? <span className="spin" /> : <Pulse size={12} />}
              <span className={`mode-pill mode-${mode}`}>{mode === "live" ? "LIVE" : "SNAPSHOT"}</span>
              {mode === "live" && liveAge && <span className="topbar-age">{liveAge}</span>}
            </button>
            {mode === "live" && (
              <button className="link-btn" onClick={refreshLive} disabled={liveLoading} title="Re-fetch live scenarios">
                <Refresh size={12} /> Refresh
              </button>
            )}
            <button
              className={`link-btn${consoleOpen ? " is-on" : ""}`}
              onClick={() => setConsoleOpen(!consoleOpen)}
              title="Toggle live API console"
            >
              <Layers size={12} /> Console
              {apiLogCount > 0 && <span className="badge mono">{apiLogCount}</span>}
            </button>
            <button className="link-btn" onClick={() => setCmdOpen(true)}>
              <Cmd size={13} /> <kbd>⌘K</kbd>
            </button>
          </div>
        </header>
      )}

      <div className="scene">
        {scene === "landing" && <Landing />}
        {scene === "mission" && <MissionControl />}
        {scene === "history" && <RunHistory />}
        {scene === "studio" && <Studio />}
        {scene === "settings" && <Settings />}
      </div>

      <CommandBar />
      <Console />
      <Toaster />
    </div>
  );
}