refactor(claude-code-hooks): extract handlers and session state

Split hook into per-concern modules:
- handlers/ directory for individual hook handlers
- session-hook-state.ts: session-level hook state management

src/hooks/claude-code-hooks/handlers/tool-execute-before-handler.ts

@@ -0,0 +1,92 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+import { loadClaudeHooksConfig } from "../config"
+import { loadPluginExtendedConfig } from "../config-loader"
+import {
+	executePreToolUseHooks,
+	type PreToolUseContext,
+} from "../pre-tool-use"
+import { appendTranscriptEntry } from "../transcript"
+import { cacheToolInput } from "../tool-input-cache"
+import type { PluginConfig } from "../types"
+import { isHookDisabled, log } from "../../../shared"
+
+export function createToolExecuteBeforeHandler(ctx: PluginInput, config: PluginConfig) {
+	return async (
+		input: { tool: string; sessionID: string; callID: string },
+		output: { args: Record<string, unknown> },
+	): Promise<void> => {
+		if (input.tool.trim() === "todowrite" && typeof output.args.todos === "string") {
+			let parsed: unknown
+			try {
+				parsed = JSON.parse(output.args.todos)
+			} catch {
+				throw new Error(
+					`[todowrite ERROR] Failed to parse todos string as JSON. ` +
+						`Received: ${
+							output.args.todos.length > 100
+								? output.args.todos.slice(0, 100) + "..."
+								: output.args.todos
+						} ` +
+						`Expected: Valid JSON array. Pass todos as an array, not a string.`,
+				)
+			}
+
+			if (!Array.isArray(parsed)) {
+				throw new Error(
+					`[todowrite ERROR] Parsed JSON is not an array. ` +
+						`Received type: ${typeof parsed}. ` +
+						`Expected: Array of todo objects. Pass todos as [{id, content, status, priority}, ...].`,
+				)
+			}
+
+			output.args.todos = parsed
+			log("todowrite: parsed todos string to array", { sessionID: input.sessionID })
+		}
+
+		const claudeConfig = await loadClaudeHooksConfig()
+		const extendedConfig = await loadPluginExtendedConfig()
+
+		appendTranscriptEntry(input.sessionID, {
+			type: "tool_use",
+			timestamp: new Date().toISOString(),
+			tool_name: input.tool,
+			tool_input: output.args,
+		})
+
+		cacheToolInput(input.sessionID, input.tool, input.callID, output.args)
+
+		if (isHookDisabled(config, "PreToolUse")) {
+			return
+		}
+
+		const preCtx: PreToolUseContext = {
+			sessionId: input.sessionID,
+			toolName: input.tool,
+			toolInput: output.args,
+			cwd: ctx.directory,
+			toolUseId: input.callID,
+		}
+
+		const result = await executePreToolUseHooks(preCtx, claudeConfig, extendedConfig)
+
+		if (result.decision === "deny") {
+			ctx.client.tui
+				.showToast({
+					body: {
+						title: "PreToolUse Hook Executed",
+						message: `[BLOCKED] ${result.toolName ?? input.tool} ${
+							result.hookName ?? "hook"
+						}: ${result.elapsedMs ?? 0}ms\n${result.inputLines ?? ""}`,
+						variant: "error" as const,
+						duration: 4000,
+					},
+				})
+				.catch(() => {})
+			throw new Error(result.reason ?? "Hook blocked the operation")
+		}
+
+		if (result.modifiedInput) {
+			Object.assign(output.args, result.modifiedInput)
+		}
+	}
+}