feat: in-memory event bus + reusable Spinner component (A2.1+A2.2) #100

[four-bytes-robby]

Closes #100

Changes

A2.1 — In-memory event bus

• New src/event-bus.ts — typed BrainEventBus with replay-on-subscribe
• status.ts publishes via brainBus.emit('status', ...) instead of writeFileSync()
• tui.tsx subscribes via brainBus.on('status', handler) instead of setInterval(poll, 200ms)
• Removed all file I/O from status→TUI path (no more status JSON files on disk)
• Removed getBrainStatusFile() — now dead code

A2.2 — Reusable Spinner component

• New src/spinner.tsx — SolidJS <Spinner> with braille animation, configurable interval + color
• tui.tsx uses <Spinner fg={fg()} /> instead of inline SPINNER array + manual spin++

Files changed: 7 (2 new, 5 modified, 0 deleted)

src/event-bus.ts    (+39 new)
src/spinner.tsx     (+21 new)
src/status.ts       (-9)
src/tui.tsx         (-14)
src/four-opencode-brain.ts (-1)
src/shared.ts       (-19)
ROADMAP.md          (9 A2.1+A2.2 checkboxes checked off)

Verification

• bun run build ✅

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Summary by cubic

Replaced file-based status polling with an in-memory event bus and added a reusable SolidJS <Spinner>. This removes disk I/O, delivers real-time TUI updates, and completes A2.1 + A2.2 acceptance criteria.

• New Features

  • Added src/event-bus.ts with a typed brainBus that replays the latest event on subscribe.
  • Added src/spinner.tsx <Spinner> using braille frames with configurable interval and color (@opentui/solid, @opentui/core).

• Refactors

  • src/status.ts now publishes via brainBus.emit('status', ...); removed status file writes.
  • src/tui.tsx subscribes with brainBus.on('status', ...); removed polling loop and inline spinner.
  • Removed getBrainStatusFile and related file I/O from src/shared.ts; updated initStatus(client) in src/four-opencode-brain.ts.
  • Uses @four-bytes/opencode-plugin-lib and @opencode-ai/plugin types as before; TUI colors sourced from theme.

^{Written for commit 98408f6. Summary will update on new commits.}