Refine workspace hovercard section indentation

[nwparker]

Summary

• keep workspace hovercard section titles flush with the card content
• indent each section body with a subtle left divider for PR/notes/live ports separation
• cover the live ports markup shape in the focused render test

Verification

• pnpm exec vitest run --config config/vitest.config.ts src/renderer/src/components/sidebar/WorktreeCardPorts.test.tsx src/renderer/src/components/sidebar/WorktreeCard.pr-display.test.tsx
• pnpm run typecheck:web
• pnpm exec oxlint src/renderer/src/components/sidebar/WorktreeCardDetailSection.tsx src/renderer/src/components/sidebar/WorktreeCardMeta.tsx src/renderer/src/components/sidebar/WorktreeCardPorts.tsx src/renderer/src/components/sidebar/WorktreeCardPorts.test.tsx
• git diff --check
• Electron visual check of PR + Notes + Live Ports hovercard