fix: login preflight auto-launches the source browser instance

nh_login_preflight assumed the per-source Chromium was already running
(panel login-test failed silently for sources whose window had been
closed); extract nh_ensure_instance (no-op when alive) and use it in
both preflight and autodiscover. Harvests were unaffected — harvest.js
already runs ensure-chromium itself.

bin/platform.sh

@@ -381,6 +381,17 @@ nh_skill_bootstrap() {  # clone(可选)+ 依赖安装 + 全量 bundle 导入 + v
 # 凭据文件:$CONF_DIR/logins/<source>.json({"url":…,"user":…,"password":…},建议 600)。
 # 配方与浏览器自动化在技能仓 login-tools.js;本层只做编排,登录失败不中断采集
 # (结果契约会如实标记付费墙)。
+nh_ensure_instance() {  # <source> 确保该源专属浏览器实例在线(已在线为无操作)
+  local source="$1"
+  if nh_is_darwin && [ -z "${CDP_PORT_OVERRIDE:-}" ]; then
+    export CDP_PORT_OVERRIDE="$(nh_cdp_port "$source")"
+    export CDP_PROFILE_OVERRIDE="$HOME/.news-harvester/profiles/${source}"
+  fi
+  [ -f "$(nh_skill_dir)/scripts/ensure-chromium.js" ] || return 0
+  (cd "$(nh_skill_dir)" && node scripts/ensure-chromium.js >/dev/null 2>&1 || true)
+  return 0
+}
+
 nh_login_preflight() {  # <source>
   local source="$1" creds tools_dir
   creds="$CONF_DIR/logins/${source}.json"
@@ -390,11 +401,7 @@ nh_login_preflight() {  # <source>
     echo "⚠️  已配置 $source 的登录凭据,但技能缺少 login-tools.js,跳过预检" >&2
     return 0
   fi
-  # 未显式指定浏览器实例时,自动使用该源的专属实例(darwin 隔离布局)
-  if nh_is_darwin && [ -z "${CDP_PORT_OVERRIDE:-}" ]; then
-    export CDP_PORT_OVERRIDE="$(nh_cdp_port "$source")"
-    export CDP_PROFILE_OVERRIDE="$HOME/.news-harvester/profiles/${source}"
-  fi
+  nh_ensure_instance "$source"
   export NH_LOGIN_USER="$(jq -r '.user // empty' "$creds" 2>/dev/null)"
   export NH_LOGIN_PASS="$(jq -r '.password // empty' "$creds" 2>/dev/null)"
   if (cd "$tools_dir" && node scripts/login-tools.js check "$source") >/dev/null 2>&1; then
@@ -416,15 +423,7 @@ nh_login_autodiscover() {  # <source>  自动发现登录流程生成配方,并
   [ -f "$creds" ] || { echo "❌ 未配置 $source 的凭据(看板「站点登录」页维护)" >&2; return 1; }
   tools_dir="$(nh_skill_dir)"
   [ -f "$tools_dir/scripts/login-tools.js" ] || { echo "❌ 技能缺少 login-tools.js" >&2; return 1; }
-  [ -f "$tools_dir/scripts/ensure-chromium.js" ] && {
-    # 确保该源的专属浏览器实例在线(darwin 隔离布局)
-    (cd "$tools_dir" && { [ -z "${CDP_PORT_OVERRIDE:-}" ] && nh_is_darwin && export CDP_PORT_OVERRIDE="$(nh_cdp_port "$source")" CDP_PROFILE_OVERRIDE="$HOME/.news-harvester/profiles/${source}"; \
-      node scripts/ensure-chromium.js >/dev/null 2>&1; })
-  }
-  if nh_is_darwin && [ -z "${CDP_PORT_OVERRIDE:-}" ]; then
-    export CDP_PORT_OVERRIDE="$(nh_cdp_port "$source")"
-    export CDP_PROFILE_OVERRIDE="$HOME/.news-harvester/profiles/${source}"
-  fi
+  nh_ensure_instance "$source"
   export NH_LOGIN_USER="$(jq -r '.user // empty' "$creds" 2>/dev/null)"
   export NH_LOGIN_PASS="$(jq -r '.password // empty' "$creds" 2>/dev/null)"
   (cd "$tools_dir" && node scripts/login-tools.js discover "$source")