fix(installer): preserve existing claude hook settings

scripts/lib/install/apply.js

@@ -1,15 +1,86 @@
 'use strict';
 
 const fs = require('fs');
+const path = require('path');
 
 const { writeInstallState } = require('../install-state');
 
+function mergeHookEntries(existingEntries, incomingEntries) {
+  const mergedEntries = [];
+  const seenEntries = new Set();
+
+  for (const entry of [...existingEntries, ...incomingEntries]) {
+    const entryKey = JSON.stringify(entry);
+    if (seenEntries.has(entryKey)) {
+      continue;
+    }
+
+    seenEntries.add(entryKey);
+    mergedEntries.push(entry);
+  }
+
+  return mergedEntries;
+}
+
+function mergeHooksIntoSettings(plan) {
+  if (!plan.adapter || plan.adapter.target !== 'claude') {
+    return;
+  }
+
+  const hooksJsonPath = path.join(plan.targetRoot, 'hooks', 'hooks.json');
+  if (!fs.existsSync(hooksJsonPath)) {
+    return;
+  }
+
+  let hooksConfig;
+  try {
+    hooksConfig = JSON.parse(fs.readFileSync(hooksJsonPath, 'utf8'));
+  } catch (error) {
+    throw new Error(`Failed to parse hooks config at ${hooksJsonPath}: ${error.message}`);
+  }
+
+  const incomingHooks = hooksConfig.hooks;
+  if (!incomingHooks || typeof incomingHooks !== 'object' || Array.isArray(incomingHooks)) {
+    return;
+  }
+
+  const settingsPath = path.join(plan.targetRoot, 'settings.json');
+  let settings = {};
+  if (fs.existsSync(settingsPath)) {
+    try {
+      settings = JSON.parse(fs.readFileSync(settingsPath, 'utf8'));
+    } catch (error) {
+      throw new Error(`Failed to parse existing settings at ${settingsPath}: ${error.message}`);
+    }
+  }
+
+  const existingHooks = settings.hooks && typeof settings.hooks === 'object' && !Array.isArray(settings.hooks)
+    ? settings.hooks
+    : {};
+  const mergedHooks = { ...existingHooks };
+
+  for (const [eventName, incomingEntries] of Object.entries(incomingHooks)) {
+    const currentEntries = Array.isArray(existingHooks[eventName]) ? existingHooks[eventName] : [];
+    const nextEntries = Array.isArray(incomingEntries) ? incomingEntries : [];
+    mergedHooks[eventName] = mergeHookEntries(currentEntries, nextEntries);
+  }
+
+  const mergedSettings = {
+    ...settings,
+    hooks: mergedHooks,
+  };
+
+  fs.mkdirSync(path.dirname(settingsPath), { recursive: true });
+  fs.writeFileSync(settingsPath, JSON.stringify(mergedSettings, null, 2) + '\n', 'utf8');
+}
+
 function applyInstallPlan(plan) {
   for (const operation of plan.operations) {
-    fs.mkdirSync(require('path').dirname(operation.destinationPath), { recursive: true });
+    fs.mkdirSync(path.dirname(operation.destinationPath), { recursive: true });
     fs.copyFileSync(operation.sourcePath, operation.destinationPath);
   }
 
+  mergeHooksIntoSettings(plan);
   writeInstallState(plan.installStatePath, plan.statePreview);
 
   return {