diff --git a/app/index.js b/app/index.js
index 81b4c3d..d67a4f0 100644
--- a/app/index.js
+++ b/app/index.js
@@ -2,7 +2,7 @@ import { loadInputs, logInputs } from './lib/inputs.js';
 import { Git } from './lib/git.js';
 import { GiteaClient } from './lib/gitea.js';
 import { OpenCode } from './lib/opencode.js';
-import { log } from './lib/util.js';
+import { log, maskSecrets } from './lib/util.js';
 
 async function main() {
   const inputs = loadInputs();
@@ -143,7 +143,9 @@ function buildResolveBranchName(target, source) {
   const runId = process.env.GITHUB_RUN_NUMBER || process.env.GITHUB_RUN_ID || '';
   const safe = (s) => s.replace(/[^a-zA-Z0-9._/-]/g, '-');
   const suffix = runId ? `-${runId}` : '';
-  return `resolve-conflict/${safe(target)}-into-${safe(source)}${suffix}`;
+  // 截斷主體長度，避免 target/source 過長使分支名稱超出 Git 限制
+  const stem = `${safe(target)}-into-${safe(source)}`.slice(0, 180);
+  return `resolve-conflict/${stem}${suffix}`;
 }
 
 /** 解衝突 PR 的描述。 */
@@ -180,6 +182,8 @@ function reportPull(pull, created) {
 }
 
 main().catch((err) => {
-  log.error(err?.stack || err?.message || String(err));
+  const detail = err?.stack || err?.message || String(err);
+  // 錯誤訊息／stack 可能夾帶 token，輸出到 CI 日誌前先遮蔽
+  log.error(maskSecrets(detail, [process.env.GITEA_TOKEN]));
   process.exit(1);
 });
diff --git a/app/lib/opencode.js b/app/lib/opencode.js
index 1190790..0d3870f 100644
--- a/app/lib/opencode.js
+++ b/app/lib/opencode.js
@@ -1,6 +1,6 @@
-import { writeFileSync, mkdtempSync } from 'node:fs';
-import { tmpdir } from 'node:os';
-import { join } from 'node:path';
+import { writeFileSync, mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir, homedir } from 'node:os';
+import { join, dirname } from 'node:path';
 import { run, log, maskSecrets } from './util.js';
 
 /**
@@ -74,33 +74,38 @@ export class OpenCode {
     const configPath = this._writeConfig();
     const prompt = buildPrompt({ ...ctx, language: this.language });
 
-    log.info(`呼叫 opencode（${this.provider}/${this.model}）分析 diff...`);
-    const result = run(
-      'opencode',
-      ['run', '--model', `${this.provider}/${this.model}`, prompt],
-      {
-        cwd: tmpdir(),
-        env: {
-          ...process.env,
-          OPENCODE_CONFIG: configPath,
-          // 確保 opencode 有可寫的 HOME / 設定目錄
-          HOME: process.env.HOME || '/root',
+    try {
+      log.info(`呼叫 opencode（${this.provider}/${this.model}）分析 diff...`);
+      const result = run(
+        'opencode',
+        ['run', '--model', `${this.provider}/${this.model}`, prompt],
+        {
+          cwd: tmpdir(),
+          env: {
+            ...process.env,
+            OPENCODE_CONFIG: configPath,
+            // 確保 opencode 有可寫的 HOME / 設定目錄
+            HOME: process.env.HOME || homedir(),
+          },
+          timeout: 5 * 60 * 1000,
         },
-        timeout: 5 * 60 * 1000,
-      },
-    );
+      );
 
-    if (result.status !== 0) {
-      log.warn(`opencode 執行失敗 (${result.status})：${maskSecrets(result.stderr).slice(0, 500)}`);
-      return null;
-    }
+      if (result.status !== 0) {
+        log.warn(`opencode 執行失敗 (${result.status})：${maskSecrets(result.stderr).slice(0, 500)}`);
+        return null;
+      }
 
-    const parsed = extractResult(result.stdout);
-    if (!parsed) {
-      log.warn('無法從 opencode 輸出解析出標題/描述');
-      return null;
+      const parsed = extractResult(result.stdout);
+      if (!parsed) {
+        log.warn('無法從 opencode 輸出解析出標題/描述');
+        return null;
+      }
+      return parsed;
+    } finally {
+      // 清理 _writeConfig 建立的暫存設定目錄，避免堆積
+      rmSync(dirname(configPath), { recursive: true, force: true });
     }
-    return parsed;
   }
 }