feat(inspector): timeline, empty/skeleton states, and retry badge

[JSisques]

Closes #77
Closes #78

Type

• New feature

Summary

• Adds InspectorTimeline component with descending timestamp sort and spine connector
• Adds InspectorEmpty and InspectorSkeleton loading/empty state components
• Adds retry badge to RequestCard using i18n template dict.card.retries
• Adds view toggle (List / Timeline) to InspectorToolbar and conditional rendering in InspectorClient

Changes

File	Change
features/inspector/components/inspector-timeline/	Timeline view with spine connector, sorted newest-first
features/inspector/components/inspector-empty/	Empty state shown when no entries
features/inspector/components/inspector-skeleton/	Skeleton loader for list and timeline modes
features/inspector/components/request-card/	Retry badge (i18n, only when attempts > 1)
features/inspector/components/inspector-toolbar/	List / Timeline view toggle buttons
features/inspector/components/inspector-client/	Conditional render: skeleton → empty → timeline/list
features/inspector/components/request-list/	Thread dict prop to RequestCard
features/inspector/i18n/en.ts + es.ts	Keys: view, empty, card.retries

Test Plan

• All inspector tests pass: pnpm test -- --testPathPattern=inspector
• Strict TDD — RED test written and confirmed failing before each GREEN implementation
• Chained PR — PR2 (feat(inspector): server action, Zustand store, and list UI #212) must merge first

Chained PR: base is feat/inspector-pr2. Retarget to main after PR2 merges.