refactor(ralph-loop): split hook into state controller and event handler modules

Extract Ralph loop lifecycle management:
- loop-state-controller.ts: start/stop/recovery state machine
- ralph-loop-event-handler.ts: event handling logic
- continuation-prompt-builder.ts, continuation-prompt-injector.ts
- completion-promise-detector.ts, loop-session-recovery.ts
- message-storage-directory.ts

src/hooks/ralph-loop/completion-promise-detector.ts

@@ -0,0 +1,90 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+import { existsSync, readFileSync } from "node:fs"
+import { log } from "../../shared/logger"
+import { HOOK_NAME } from "./constants"
+
+interface OpenCodeSessionMessage {
+	info?: { role?: string }
+	parts?: Array<{ type: string; text?: string }>
+}
+
+function escapeRegex(str: string): string {
+	return str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")
+}
+
+function buildPromisePattern(promise: string): RegExp {
+	return new RegExp(`<promise>\\s*${escapeRegex(promise)}\\s*</promise>`, "is")
+}
+
+export function detectCompletionInTranscript(
+	transcriptPath: string | undefined,
+	promise: string,
+): boolean {
+	if (!transcriptPath) return false
+
+	try {
+		if (!existsSync(transcriptPath)) return false
+
+		const content = readFileSync(transcriptPath, "utf-8")
+		const pattern = buildPromisePattern(promise)
+		const lines = content.split("\n").filter((line) => line.trim())
+
+		for (const line of lines) {
+			try {
+				const entry = JSON.parse(line) as { type?: string }
+				if (entry.type === "user") continue
+				if (pattern.test(line)) return true
+			} catch {
+				continue
+			}
+		}
+		return false
+	} catch {
+		return false
+	}
+}
+
+export async function detectCompletionInSessionMessages(
+	ctx: PluginInput,
+	options: {
+		sessionID: string
+		promise: string
+		apiTimeoutMs: number
+		directory: string
+	},
+): Promise<boolean> {
+	try {
+		const response = await Promise.race([
+			ctx.client.session.messages({
+				path: { id: options.sessionID },
+				query: { directory: options.directory },
+			}),
+			new Promise<never>((_, reject) =>
+				setTimeout(() => reject(new Error("API timeout")), options.apiTimeoutMs),
+			),
+		])
+
+		const messages = (response as { data?: unknown[] }).data ?? []
+		if (!Array.isArray(messages)) return false
+
+		const assistantMessages = (messages as OpenCodeSessionMessage[]).filter(
+			(msg) => msg.info?.role === "assistant",
+		)
+		const lastAssistant = assistantMessages[assistantMessages.length - 1]
+		if (!lastAssistant?.parts) return false
+
+		const pattern = buildPromisePattern(options.promise)
+		const responseText = lastAssistant.parts
+			.filter((p) => p.type === "text")
+			.map((p) => p.text ?? "")
+			.join("\n")
+
+		return pattern.test(responseText)
+	} catch (err) {
+		log(`[${HOOK_NAME}] Session messages check failed`, {
+			sessionID: options.sessionID,
+			error: String(err),
+		})
+		return false
+	}
+}