feat: simplify event model + extract EventBus + fix CI #113

[four-bytes-robby]

Closes #113

Simplified Event Model

status?: "init" | "busy" | "ready" | "error"
statusText?: string
current?: number
total?: number
version?: string
error?: string

Changes

• event-bus.ts: EventBus extracted to @four-bytes/opencode-plugin-lib v0.3.0, brain keeps only BrainStatusEvent type
• status.ts: StatusOpts simplified (no scanning/searching/ingesting/progress), all states map to 4-status model
• tui.tsx: handleStatus 7→4 branches, ready always shows 'ready' (toast carries result)
• four-opencode-brain.ts: removed all flag params from updateStatus calls
• Bugfix: toast import was missing (root cause of stuck scanning)
• CI: FORCE_JAVASCRIPT_ACTIONS_TO_NODE24 in codeql.yml
• v1.7.0

---

Summary by cubic

Simplified the event model to four statuses and moved the EventBus to @four-bytes/opencode-plugin-lib v0.3.0. This reduces TUI logic, fixes the stuck scanning bug, and ensures CodeQL uses Node 24.

• Refactors

  • Switched to shared EventBus; BrainStatusEvent now only has status, statusText, current, total, version, error.
  • Unified status model to init/busy/ready/error; removed scanning/searching/ingesting/progress flags.
  • Simplified TUI handling to four branches; idle always shows "ready".
  • Cleaned up updateStatus calls and progress callbacks to use current/total; improved ingest/scanning toasts.

• Bug Fixes

  • Added missing toast import that caused scanning to freeze.

^{Written for commit 8810a59. Summary will update on new commits.}