[UX] oclite: Rich status bar with streaming metrics

[randomm]

Description

Add a persistent status bar during streaming that shows key information inline.

Target UX (from sketch)

◆ Ruminating... (Esc to interrupt · ctrl+t to hide tasks · 15s · ↓ 342 tokens · shift+↑/↓ to select)

Requirements

• Show spinner state with elapsed time
• Show token count (updating in real-time)
• Show keyboard shortcuts contextually
• Show Esc to interrupt during streaming
• Update in-place (single line, overwritten)

Files

• packages/opencode/src/cli/lite/index.ts — streaming loop
• packages/opencode/src/cli/lite/spinner.ts — current spinner (extend or replace)
• packages/opencode/src/cli/lite/bottombar.ts — prompt area

[randomm]

Completed in commit 0a96085. Spinner shows elapsed time: ⠋ Thinking · 3s. Rich status bar deferred — research showed inline status is the proven pattern (#74).