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/loop-state-controller.ts

@@ -0,0 +1,81 @@
+import type { RalphLoopOptions, RalphLoopState } from "./types"
+import {
+	DEFAULT_COMPLETION_PROMISE,
+	DEFAULT_MAX_ITERATIONS,
+	HOOK_NAME,
+} from "./constants"
+import { clearState, incrementIteration, readState, writeState } from "./storage"
+import { log } from "../../shared/logger"
+
+export function createLoopStateController(options: {
+	directory: string
+	stateDir: string | undefined
+	config: RalphLoopOptions["config"] | undefined
+}) {
+	const directory = options.directory
+	const stateDir = options.stateDir
+	const config = options.config
+
+	return {
+		startLoop(
+			sessionID: string,
+			prompt: string,
+			loopOptions?: {
+				maxIterations?: number
+				completionPromise?: string
+				ultrawork?: boolean
+			},
+		): boolean {
+			const state: RalphLoopState = {
+				active: true,
+				iteration: 1,
+				max_iterations:
+					loopOptions?.maxIterations ??
+					config?.default_max_iterations ??
+					DEFAULT_MAX_ITERATIONS,
+				completion_promise:
+					loopOptions?.completionPromise ??
+					DEFAULT_COMPLETION_PROMISE,
+				ultrawork: loopOptions?.ultrawork,
+				started_at: new Date().toISOString(),
+				prompt,
+				session_id: sessionID,
+			}
+
+			const success = writeState(directory, state, stateDir)
+			if (success) {
+				log(`[${HOOK_NAME}] Loop started`, {
+					sessionID,
+					maxIterations: state.max_iterations,
+					completionPromise: state.completion_promise,
+				})
+			}
+			return success
+		},
+
+		cancelLoop(sessionID: string): boolean {
+			const state = readState(directory, stateDir)
+			if (!state || state.session_id !== sessionID) {
+				return false
+			}
+
+			const success = clearState(directory, stateDir)
+			if (success) {
+				log(`[${HOOK_NAME}] Loop cancelled`, { sessionID, iteration: state.iteration })
+			}
+			return success
+		},
+
+		getState(): RalphLoopState | null {
+			return readState(directory, stateDir)
+		},
+
+		clear(): boolean {
+			return clearState(directory, stateDir)
+		},
+
+		incrementIteration(): RalphLoopState | null {
+			return incrementIteration(directory, stateDir)
+		},
+	}
+}