Dashboard: add vim motions (j/k/h/l/g/G) to pipeline screen

[chrisands]

Problem

The pipeline screen in dashboard/ only accepts arrow keys for navigation:

• up / down to move the cursor through the application list
• left / right to switch between tabs (EVALUATED, APPLIED, INTERVIEW, TOP ≥4, SKIP)

There are no shortcuts to jump to the top or bottom of the list, and users coming from vim/less/k9s/lazygit have to leave the home row to navigate.

Proposed change

Add vim-style motions to dashboard/internal/ui/screens/pipeline.go:

Key	Action
j	cursor down (same as down)
k	cursor up (same as up)
h	previous tab (same as left)
l	next tab (same as right)
g	jump to first row in current tab
G	jump to last row in current tab

g/G should also reset scrollOffset / call adjustScroll() so the selection stays visible, and trigger loadCurrentReport() so the preview pane updates.

The existing arrow-key, f (next tab), enter, s (sort), etc. bindings stay unchanged — this is additive.

Rationale

• Zero cost for non-vim users (arrow keys still work).
• Consistent with every other TUI in the career-ops workflow that uses bubbletea/lipgloss (less, k9s, lazygit, gh pr view --web, etc.).
• g/G fills a real functional gap — today there's no fast way to reach the bottom of a long application list.

I have a patch and can open a PR.