feat(ui): implement PanelHeader component for dashboard modules

[sulaimonifeoluwa4-blip]

Closes #190

Description

This PR addresses visual inconsistencies across our dashboard layouts by introducing a standardized <PanelHeader /> component. This establishes a singular pattern for title rows, subtitles, and action alignment across various dashboard modules, aligning with the goal outlined in #97.

Changes

• 🧱 New Component: Built src/components/PanelHeader.tsx supporting typed slots for title, subtitle, and contextual actions.
• 🛠️ Dashboard Adoption: Refactored 3 core dashboard panels to unify their headers:
  1. Analytics Chart Panel (src/components/dashboard/ChartPanel.tsx)
  2. System Stats Panel (src/components/dashboard/StatsPanel.tsx)
  3. Activity Timeline Panel (src/components/dashboard/TimelinePanel.tsx)
• 🎨 Visual Consistency: Eliminated ad-hoc padding/font mismatches across individual module title blocks.

Acceptance Criteria Verification

• Typography & Spacing: All modified panels now share identical title heights, paddings, and typographic hierarchies.
• Adoption Metrics: Migrated 3 operational dashboard widgets away from custom header implementations.
• Storybook/Compilation: Bundle compiles with zero TypeScript compilation or linting infractions.

How to Test

1. Spin up the frontend development server: npm run dev
2. Open the main dashboard route.
3. Inspect the Chart, Stats, and Timeline widgets to verify identical alignment, spacing, and header layouts across viewports.

[vercel]

@Aycode01 is attempting to deploy a commit to the josephchimebuka's projects Team on Vercel.

A member of the Team first needs to authorize it.