refactor(cli): split doctor/model-resolution and run/events into focused modules

Doctor checks:
- model-resolution-cache.ts, model-resolution-config.ts
- model-resolution-details.ts, model-resolution-effective-model.ts
- model-resolution-types.ts, model-resolution-variant.ts

Run events:
- event-formatting.ts, event-handlers.ts
- event-state.ts, event-stream-processor.ts

src/cli/run/event-handlers.ts

@@ -0,0 +1,120 @@
+import pc from "picocolors"
+import type {
+  RunContext,
+  EventPayload,
+  SessionIdleProps,
+  SessionStatusProps,
+  SessionErrorProps,
+  MessageUpdatedProps,
+  MessagePartUpdatedProps,
+  ToolExecuteProps,
+  ToolResultProps,
+} from "./types"
+import type { EventState } from "./event-state"
+import { serializeError } from "./event-formatting"
+
+export function handleSessionIdle(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "session.idle") return
+
+  const props = payload.properties as SessionIdleProps | undefined
+  if (props?.sessionID === ctx.sessionID) {
+    state.mainSessionIdle = true
+  }
+}
+
+export function handleSessionStatus(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "session.status") return
+
+  const props = payload.properties as SessionStatusProps | undefined
+  if (props?.sessionID === ctx.sessionID && props?.status?.type === "busy") {
+    state.mainSessionIdle = false
+  }
+}
+
+export function handleSessionError(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "session.error") return
+
+  const props = payload.properties as SessionErrorProps | undefined
+  if (props?.sessionID === ctx.sessionID) {
+    state.mainSessionError = true
+    state.lastError = serializeError(props?.error)
+    console.error(pc.red(`\n[session.error] ${state.lastError}`))
+  }
+}
+
+export function handleMessagePartUpdated(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "message.part.updated") return
+
+  const props = payload.properties as MessagePartUpdatedProps | undefined
+  if (props?.info?.sessionID !== ctx.sessionID) return
+  if (props?.info?.role !== "assistant") return
+
+  const part = props.part
+  if (!part) return
+
+  if (part.type === "text" && part.text) {
+    const newText = part.text.slice(state.lastPartText.length)
+    if (newText) {
+      process.stdout.write(newText)
+      state.hasReceivedMeaningfulWork = true
+    }
+    state.lastPartText = part.text
+  }
+}
+
+export function handleMessageUpdated(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "message.updated") return
+
+  const props = payload.properties as MessageUpdatedProps | undefined
+  if (props?.info?.sessionID !== ctx.sessionID) return
+  if (props?.info?.role !== "assistant") return
+
+  state.hasReceivedMeaningfulWork = true
+  state.messageCount++
+}
+
+export function handleToolExecute(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "tool.execute") return
+
+  const props = payload.properties as ToolExecuteProps | undefined
+  if (props?.sessionID !== ctx.sessionID) return
+
+  const toolName = props?.name || "unknown"
+  state.currentTool = toolName
+
+  let inputPreview = ""
+  if (props?.input) {
+    const input = props.input
+    if (input.command) {
+      inputPreview = ` ${pc.dim(String(input.command).slice(0, 60))}`
+    } else if (input.pattern) {
+      inputPreview = ` ${pc.dim(String(input.pattern).slice(0, 40))}`
+    } else if (input.filePath) {
+      inputPreview = ` ${pc.dim(String(input.filePath))}`
+    } else if (input.query) {
+      inputPreview = ` ${pc.dim(String(input.query).slice(0, 40))}`
+    }
+  }
+
+  state.hasReceivedMeaningfulWork = true
+  process.stdout.write(`\n${pc.cyan(">")} ${pc.bold(toolName)}${inputPreview}\n`)
+}
+
+export function handleToolResult(ctx: RunContext, payload: EventPayload, state: EventState): void {
+  if (payload.type !== "tool.result") return
+
+  const props = payload.properties as ToolResultProps | undefined
+  if (props?.sessionID !== ctx.sessionID) return
+
+  const output = props?.output || ""
+  const maxLen = 200
+  const preview = output.length > maxLen ? output.slice(0, maxLen) + "..." : output
+
+  if (preview.trim()) {
+    const lines = preview.split("\n").slice(0, 3)
+    process.stdout.write(pc.dim(`   └─ ${lines.join("\n      ")}\n`))
+  }
+
+  state.currentTool = null
+  state.lastPartText = ""
+}