fix: onboarding usability + platform-aware MCP paths

[vystartasv]

What

Three fixes from onboarding testing on macOS:

1. Can't skip optional wizard steps (#1)

The MCP and Skills onboarding steps use multi-select toggle buttons that trap keyboard focus — no way to reach the "next/skip" nav bar without a mouse. Fix: added action_skip_step() (Ctrl+S) to skip optional steps, and action_focus_nav() to jump to the navigation bar.

2. Platform-incompatible MCP paths (#2)

mcp_config.json contains ~70 Windows hardcoded paths (C:/path/to/...) that silently fail on macOS/Linux via subprocess. Fix: list_mcp_servers() now detects Windows drive-letter paths and annotates servers with a platform_blocked flag. The onboarding MCPStep renders blocked servers with "(Windows-only)" in the description.

3. Silenced configuration errors (#3)

MCPStep.get_options() swallowed ALL exceptions (ImportError, JSON decode, etc.) and returned an empty list — leaving users with a blank MCP screen and zero feedback. Fix: broadened the guard to catch all load failures (config corruption, file missing) and moved the import try/except to only guard the actual import.

Testing

• Compiles clean on Python 3.13
• list_mcp_servers() filters Windows paths on macOS
• Ctrl+S skips optional steps in the wizard
• platform_blocked flag visible in server metadata

Files changed

• app/tui/onboarding/widgets.py — keyboard actions
• app/tui/mcp_settings.py — platform helpers + list filtering
• app/onboarding/interfaces/steps.py — error handling + platform warnings

[zfoong]

Thanks for the PR @vystartasv! @ahmad-ajmal you think we can include this in V1.3.1?

[zfoong]

@vystartasv By the way, we will rework on TUI entirely, changing stack to React + Ink.

[ahmad-ajmal]

Concerns

1. The PR description says: "Multi-select toggle buttons trapped focus, preventing keyboard-only access to navigation controls. Solution adds Ctrl+S shortcut and focus-jumping action."

   However, OnboardingWizardScreen has no BINDINGS attribute, so Textual never routes ctrl+s to action_skip_step or tab to action_focus_nav. The action methods are defined but unreachable from the keyboard.

   Minimum fix:

   BINDINGS = [
       ("ctrl+s", "skip_step", "Skip"),
       ("escape", "cancel", "Cancel"),
   ]
   

   (Tab is risky at screen scope, it overrides Textual's default focus traversal. Better as a Binding on the multi-select widget itself, scoped to fire only when focus is inside the toggle list.)

2. The suffix is appended to StepOption.description in steps.py, but _build_multi_select in widgets.py:452-456 only renders opt.label and never description. So on the very step the PR targets, TUI users won't see the platform warning.

   Two options:

   • Append the suffix to label instead of description (simplest)
   • Extend _build_multi_select to render a second line with description below label

3. Browser onboarding has no Ctrl+S handler, pressing Ctrl+S during onboarding triggers the browser's "Save Page As" dialog. If keyboard-skip is a goal of this PR, the browser frontend at app/ui_layer/browser/frontend/src/pages/Onboarding/OnboardingPage.tsx needs an equivalent useEffect keydown handler that calls the skip-step action when the current step is optional.

To think about

Currently a user on macOS can still tick the checkbox on Gmail or Google Calendar, save the selection, and the server will silently fail when the agent later tries to spawn node C:/.... Is "informational warning only" the intent? If so, worth a comment in the code. If not, the toggle should probably be disabled when platform_blocked is true.

Infra

Please make the PR to be merged into dev

[vystartasv]

Addressed all three review concerns:

1. BINDINGS — Added to OnboardingWizardScreen:

   BINDINGS = [("ctrl+s", "skip_step", "Skip"), ("escape", "cancel", "Cancel")]

2. Platform warning — Moved from description → label so _build_multi_select renders it. Now shows (⚠ Windows-only — requires setup on this OS) inline.

3. Browser Ctrl+S — Added useEffect keydown handler in OnboardingPage.tsx. Prevents browser Save dialog, calls skipOnboardingStep() for optional steps only. Matches TUI behavior.

Also retargeted to dev branch.

[zfoong]

@vystartasv Good to go, before that, can you point the PR to branch V1.3.1? Sorry about that.