Fix platform capabilities panel styling and responsiveness

[jasontaylordev]

Improves the platform capabilities panel to be more consistent with the rest of the ServicePulse UI.

Changes:

• Match card border style to the rest of the site (no rounded corners, no coloured left-border accents)
• Remove tick/cross status icon from card header - status is already conveyed by the dots and badge
• Restructure card header into a single aligned flex row (title, indicators, badge, hide button)
• Fix hide button overlapping the status badge
• Fix cards not stacking vertically at narrow viewports
• Remove description text truncation - text now wraps fully
• Use shared btn btn-primary styles for action buttons
• Fix layout jump on load when badge is not yet visible
• Clean up dead CSS and undefined CSS custom variables

Reviewer Checklist

• Components are broken down into sensible and maintainable sub-components.
• Styles are scoped to the component using it. If multiple components need to share CSS, then a .css file is created containing the shared CSS and imported into component scoped style sections.
• Naming is consistent with existing code, and adequately describes the component or function being introduced
• Only functions utilizing Vue state or lifecycle hooks are named as composables (i.e. starting with 'use');
• No module-level state is being introduced. If so, request the PR author to move the state to the corresponding Pinia store.