docs: 修正全部文档使其与源码实现一致

- Plugin.Start(sdk *PluginSDK) 接口签名改为指针
- 方法表重写: 移除 CallLLM/QueryKnowledge/SetMemory 等不存在方法
- IOInjector 参数顺序修正为 (source, channel, text)
- 删除虚构 SDKConfig, 替换为实际 New() 构造函数签名
- .hmap 内容描述一致化 (plugin.so + plugin.dll + main.lua)
- 添加 meta/ 包元数据文件

example/webfetch/go.mod

@@ -0,0 +1,7 @@
+module webfetch
+
+go 1.25.0
+
+require gitcode.com/JianFeeeee/homeagent-sdk v0.0.0-20260708004841-e9bdcf9304b0
+
+replace gitcode.com/JianFeeeee/homeagent-sdk => ../../.

example/webfetch/plg.json

@@ -0,0 +1,11 @@
+{
+  "name": "webfetch",
+  "name_zh": "网页抓取",
+  "name_en": "webfetch",
+  "version": "1.0.0",
+  "description": "网页内容抓取工具，使用无头 Chromium 浏览器获取网页文字内容",
+  "author": "HomeAgent",
+  "entry": "plugin.so",
+  "tags": ["web", "fetch"],
+  "targets": "linux/amd64"
+}

example/webfetch/plugin.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"regexp"
+	"strings"
+	"time"
+
+	"gitcode.com/JianFeeeee/homeagent-sdk/sdk"
+)
+
+type Plugin struct {
+	name string
+	sdk  *sdk.PluginSDK
+}
+
+func (p *Plugin) Name() string { return p.name }
+
+func (p *Plugin) Start(s *sdk.PluginSDK) error {
+	s.SetAutoRestart(true)
+	p.sdk = s
+
+	s.RegisterTool("web_fetch", sdk.ToolDef{
+		Name:        "web_fetch",
+		Description: "获取网页文字内容。使用无头 Chromium 浏览器渲染页面后提取正文文字，返回标题和前 5000 字符。适用于需要查看网页内容的场景。",
+		Parameters: map[string]interface{}{
+			"type": "object",
+			"properties": map[string]interface{}{
+				"url":  map[string]interface{}{"type": "string", "description": "要访问的网页 URL"},
+				"wait": map[string]interface{}{"type": "integer", "description": "等待秒数（用于 JS 渲染页面，默认 0）"},
+			},
+			"required": []string{"url"},
+		},
+	}, p.handleWebFetch)
+
+	log.Printf("[%s] plugin started", p.name)
+	return nil
+}
+
+func (p *Plugin) Stop() error { return nil }
+
+func convInt64(v interface{}) (int64, error) {
+	switch x := v.(type) {
+	case float64:
+		return int64(x), nil
+	case int64:
+		return x, nil
+	case json.Number:
+		return x.Int64()
+	case string:
+		return 0, fmt.Errorf("cannot convert string to int64")
+	default:
+		return 0, fmt.Errorf("cannot convert %T to int64", v)
+	}
+}
+
+func (p *Plugin) handleWebFetch(args map[string]interface{}) (interface{}, error) {
+	url, _ := args["url"].(string)
+	if url == "" {
+		return nil, fmt.Errorf("url is required")
+	}
+	waitSec, _ := convInt64(args["wait"])
+
+	if waitSec > 0 {
+		time.Sleep(time.Duration(waitSec) * time.Second)
+	}
+
+	var html string
+	chromiumPath := "/usr/local/bin/chromium"
+	if _, err := os.Stat(chromiumPath); err == nil {
+		var out bytes.Buffer
+		argsList := []string{"--headless", "--disable-gpu", "--no-sandbox", "--dump-dom", url}
+		cmd := exec.Command(chromiumPath, argsList...)
+		cmd.Stdout = &out
+		cmd.Stderr = nil
+		if err := cmd.Run(); err != nil {
+			return nil, fmt.Errorf("chromium: %w", err)
+		}
+		html = out.String()
+	} else {
+		resp, err := http.Get(url)
+		if err != nil {
+			return nil, fmt.Errorf("http get: %w", err)
+		}
+		defer resp.Body.Close()
+		body, err := io.ReadAll(resp.Body)
+		if err != nil {
+			return nil, fmt.Errorf("read body: %w", err)
+		}
+		html = string(body)
+	}
+
+	title := ""
+	if m := regexp.MustCompile(`<title>([^<]+)</title>`).FindStringSubmatch(html); len(m) > 1 {
+		title = m[1]
+	}
+
+	var textOut bytes.Buffer
+	pyCmd := exec.Command("python3", "-c", `
+import sys, re, html
+raw = sys.stdin.read()
+text = re.sub(r'<[^>]+>', ' ', raw)
+text = re.sub(r'\s+', ' ', text).strip()
+text = html.unescape(text)
+sys.stdout.write(text)
+`)
+	pyCmd.Stdin = strings.NewReader(html)
+	pyCmd.Stdout = &textOut
+	pyCmd.Stderr = nil
+	pyCmd.Run()
+	text := strings.TrimSpace(textOut.String())
+
+	origLen := len(text)
+	truncated := origLen > 5000
+	if truncated {
+		text = text[:5000]
+	}
+
+	result := ""
+	if title != "" {
+		result = fmt.Sprintf("标题: %s\nURL: %s\n\n", title, url)
+	}
+	result += text
+	if truncated {
+		result += fmt.Sprintf("\n\n...（内容过长，仅显示前 5000 字符，共 %d 字符）", origLen)
+	}
+
+	return map[string]interface{}{
+		"content": result,
+		"title":   title,
+	}, nil
+}
+
+func NewPlugin(name string, config map[string]interface{}) (sdk.Plugin, error) {
+	return &Plugin{name: name}, nil
+}