fix: onboarding usability + platform-aware MCP paths

app/onboarding/interfaces/steps.py

@@ -522,28 +522,35 @@ def get_options(self) -> List[StepOption]:
         try:
             from app.tui.mcp_settings import list_mcp_servers
             servers = list_mcp_servers()
-
-            # Create a lookup by name
-            server_lookup = {s["name"]: s for s in servers}
-
-            # Return only recommended servers that exist in config
-            options = []
-            for name, (icon, requires_setup) in self.RECOMMENDED_SERVERS.items():
-                if name in server_lookup:
-                    server = server_lookup[name]
-                    label = server["name"].replace("-", " ").replace(" mcp", "").title()
-                    options.append(StepOption(
-                        value=server["name"],
-                        label=label,
-                        description=server.get("description", f"MCP server: {server['name']}"),
-                        default=server.get("enabled", False),
-                        icon=icon,
-                        requires_setup=requires_setup
-                    ))
-            return options
-        except ImportError:
+        except Exception:
+            # If MCP config is completely broken, show nothing rather than
+            # crashing the wizard — the user can configure later in Settings.
             return []
 
+        # Create a lookup by name
+        server_lookup = {s["name"]: s for s in servers}
+
+        # Return only recommended servers that exist in config
+        options = []
+        for name, (icon, requires_setup) in self.RECOMMENDED_SERVERS.items():
+            if name in server_lookup:
+                server = server_lookup[name]
+                label = server["name"].replace("-", " ").replace(" mcp", "").title()
+                # Append platform warning to description when server paths
+                # are incompatible with the current OS
+                desc = server.get("description", f"MCP server: {server['name']}")
+                if server.get("platform_blocked"):
+                    label += " (⚠ Windows-only — requires setup on this OS)"
+                options.append(StepOption(
+                    value=server["name"],
+                    label=label,
+                    description=desc,
+                    default=server.get("enabled", False),
+                    icon=icon,
+                    requires_setup=requires_setup,
+                ))
+        return options
+
     def validate(self, value: Any) -> tuple[bool, Optional[str]]:
         # Value should be a list of server names
         if not isinstance(value, list):

app/tui/mcp_settings.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import json
+import sys
 from pathlib import Path
 from typing import Dict, List, Optional, Any
 
@@ -13,6 +14,23 @@
 MCP_CONFIG_PATH = APP_CONFIG_PATH / "mcp_config.json"
 
 
+def _is_windows_path(path: str) -> bool:
+    """Check if a path uses Windows drive-letter syntax (e.g. C:/...)."""
+    return bool(path) and len(path) >= 2 and path[0].isalpha() and path[1] == ":"
+
+
+def _path_usable_on_current_platform(command: str, args: list) -> bool:
+    """Return False if command/args reference paths not valid on this OS."""
+    if sys.platform == "win32":
+        return True
+    if _is_windows_path(command):
+        return False
+    for arg in args or []:
+        if _is_windows_path(arg):
+            return False
+    return True
+
+
 def load_mcp_config() -> MCPConfig:
     """Load MCP configuration from file."""
     try:
@@ -34,10 +52,27 @@ def save_mcp_config(config: MCPConfig) -> bool:
 
 
 def list_mcp_servers() -> List[Dict[str, Any]]:
-    """Get list of configured MCP servers with their status."""
-    config = load_mcp_config()
+    """Get list of configured MCP servers with their status.
+
+    Servers with platform-incompatible paths (e.g. Windows paths on macOS)
+    are annotated with a ``platform_blocked`` flag so the UI can explain why
+    they cannot be started.
+    """
+    try:
+        config = load_mcp_config()
+    except Exception as exc:
+        logger.error(f"Failed to load MCP config: {exc}")
+        return []
     servers = []
     for server in config.mcp_servers:
+        platform_blocked = not _path_usable_on_current_platform(
+            server.command or "", getattr(server, "args", []) or []
+        )
+        if platform_blocked:
+            logger.debug(
+                "MCP server %s has platform-specific paths — skipping on %s",
+                server.name, sys.platform,
+            )
         servers.append({
             "name": server.name,
             "description": server.description,
@@ -46,6 +81,7 @@ def list_mcp_servers() -> List[Dict[str, Any]]:
             "command": server.command,
             "action_set": server.resolved_action_set_name,
             "env": server.env,
+            "platform_blocked": platform_blocked,
         })
     return servers
 

app/tui/onboarding/widgets.py

@@ -286,6 +286,11 @@ class OnboardingWizardScreen(Screen):
 
     CSS = ONBOARDING_CSS
 
+    BINDINGS = [
+        ("ctrl+s", "skip_step", "Skip"),
+        ("escape", "cancel", "Cancel"),
+    ]
+
     def __init__(self, handler: "TUIHardOnboarding"):
         super().__init__()
         self._handler = handler
@@ -695,7 +700,19 @@ def _complete(self) -> None:
         self._handler.on_complete(cancelled=False)
         self.app.pop_screen()
 
+    def action_skip_step(self) -> None:
+        """Skip the current optional step (Ctrl+S)."""
+        step = self._handler.get_step(self._current_step)
+        if not step.required:
+            self._skip_step()
+
     def action_cancel(self) -> None:
         """Handle Escape key to cancel wizard."""
         self._handler.on_complete(cancelled=True)
         self.app.pop_screen()
+
+    def action_focus_nav(self) -> None:
+        """Focus the navigation bar (Tab)."""
+        nav = self.query_one("#nav-actions")
+        if hasattr(nav, 'focus'):
+            nav.focus()

app/ui_layer/browser/frontend/src/pages/Onboarding/OnboardingPage.tsx

@@ -509,6 +509,21 @@ export function OnboardingPage() {
   }, [onboardingStep, selectedValue, textValue, orModel, proxiedVia, ollamaUrl, formValues, submitOnboardingStep])
 
   const handleSkip = useCallback(() => skipOnboardingStep(), [skipOnboardingStep])
+
+  // Ctrl+S to skip optional steps (matches TUI behavior)
+  useEffect(() => {
+    const handler = (e: KeyboardEvent) => {
+      if ((e.ctrlKey || e.metaKey) && e.key === 's') {
+        if (onboardingStep && !onboardingStep.required) {
+          e.preventDefault()
+          skipOnboardingStep()
+        }
+      }
+    }
+    window.addEventListener('keydown', handler)
+    return () => window.removeEventListener('keydown', handler)
+  }, [onboardingStep, skipOnboardingStep])
+
   const handleBack = useCallback(() => goBackOnboardingStep(), [goBackOnboardingStep])
 
   const isMultiSelect = onboardingStep?.name === 'mcp' || onboardingStep?.name === 'skills'