feat(web-console): cherry-pick React web console GUI from gary-the-ai fork

Cherry-pick the Hermes Web Console from gary-the-ai/hermes-web-console-gui.
React + TypeScript frontend with Vite, Python aiohttp backend API.

Components:
- web_console/ — React frontend (chat, sessions, memory, settings, skills,
  gateway config, cron, workspace, tools, browser, insights pages)
- gateway/web_console/ — Python backend API (23 endpoints, SSE event bus,
  11 service modules)
- gateway/platforms/api_server_ui.py — embedded browser UI for API server
- gateway/platforms/api_server.py — route registration refactored into
  _register_routes(), web console mounted via maybe_register_web_console()
- run-gui.sh / setup-gui.sh — one-command launch and setup scripts
- tests/gateway/test_api_server_gui_mount.py — 4 integration tests (passing)
- tests/web_console/ — 13 backend test files (51 passing)
- docs/plans/ — implementation plan, API schema, frontend architecture

Fix: added missing ModelContextError class and CRON_MIN_CONTEXT_TOKENS to
cron/scheduler.py (pre-existing import bug).

Closes #325

gateway/web_console/api/version.py

@@ -0,0 +1,72 @@
+"""Version info API route for the Hermes Web Console backend."""
+
+from __future__ import annotations
+
+import logging
+import aiohttp
+from aiohttp import web
+
+logger = logging.getLogger("version_api")
+
+async def handle_get_version(request: web.Request) -> web.Response:
+    try:
+        from hermes_cli import __version__, __release_date__
+    except ImportError:
+        __version__ = "unknown"
+        __release_date__ = "unknown"
+
+    return web.json_response({
+        "ok": True,
+        "version": __version__,
+        "release_date": __release_date__,
+    })
+
+async def handle_check_update(request: web.Request) -> web.Response:
+    """Check PyPI for the latest version of hermes-agent."""
+    try:
+        from hermes_cli import __version__
+    except ImportError:
+        __version__ = "0.0.0"
+
+    try:
+        async with aiohttp.ClientSession() as session:
+            async with session.get("https://pypi.org/pypi/hermes-agent/json", timeout=5) as resp:
+                if resp.status == 200:
+                    data = await resp.json()
+                    latest_version = data["info"]["version"]
+                    
+                    # Basic comparison assuming semantic versioning like 0.6.1 vs 0.6.0
+                    # For simplicity, we just check if it's different.
+                    # Normally we'd use packaging.version.parse, but standard string comparison
+                    # or exact matching is often enough to say "update available" if __version__ != latest
+                    has_update = __version__ != "unknown" and latest_version != __version__
+                    
+                    # Attempt to fetch changelog or description for the new version
+                    releases = data.get("releases", {})
+                    latest_release_info = releases.get(latest_version, [])
+                    changelog = ""
+                    if latest_release_info:
+                        # Extract some basic info, like if there's a Github release description
+                        # Actually PyPI JSON doesn't contain the markdown changelog for that release easily.
+                        # We'll just provide the project url if needed.
+                        pass
+                    
+                    return web.json_response({
+                        "ok": True,
+                        "current_version": __version__,
+                        "latest_version": latest_version,
+                        "has_update": has_update,
+                        "project_url": data["info"]["project_urls"].get("Homepage", "https://pypi.org/project/hermes-agent/")
+                    })
+                return web.json_response({
+                    "ok": False,
+                    "error": f"Failed to fetch PyPI data: {resp.status}"
+                }, status=502)
+    except Exception as e:
+        logger.error(f"Failed to check for updates: {e}")
+        return web.json_response({"ok": False, "error": str(e)}, status=500)
+
+
+def register_version_api_routes(app: web.Application) -> None:
+    app.router.add_get("/api/gui/version", handle_get_version)
+    app.router.add_get("/api/gui/version/check", handle_check_update)