feat: initial scaffold of awesome-coding-agents tracker

Go updater that fetches AI agent coding tool repo stats via GitHub GraphQL
(batched, one query), sorts by star count, appends a daily snapshot to
data/history.jsonl, and regenerates README.md from templates/readme.tmpl.
Daily workflow at .github/workflows/update.yml refreshes rankings and
commits changes. Seed list in data/agents.yml covers 19 tracked repos.

github.go

@@ -0,0 +1,131 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"sort"
+	"strings"
+	"time"
+)
+
+type Stat struct {
+	Owner         string
+	Repo          string
+	Category      string
+	Notes         string
+	Description   string
+	Stars         int
+	Language      string
+	PushedAt      time.Time
+	URL           string
+	NameWithOwner string
+}
+
+type repoNode struct {
+	StargazerCount  int    `json:"stargazerCount"`
+	Description     string `json:"description"`
+	PrimaryLanguage *struct {
+		Name string `json:"name"`
+	} `json:"primaryLanguage"`
+	PushedAt      time.Time `json:"pushedAt"`
+	URL           string    `json:"url"`
+	NameWithOwner string    `json:"nameWithOwner"`
+}
+
+type graphQLResponse struct {
+	Data   map[string]*repoNode `json:"data"`
+	Errors []struct {
+		Message string `json:"message"`
+		Path    []any  `json:"path"`
+	} `json:"errors"`
+}
+
+const repoFields = `
+		stargazerCount
+		description
+		primaryLanguage { name }
+		pushedAt
+		url
+		nameWithOwner
+	`
+
+func fetchStats(token string, agents []Agent) ([]Stat, error) {
+	var b strings.Builder
+	b.WriteString("query {\n")
+	for i, a := range agents {
+		fmt.Fprintf(&b, "  r%d: repository(owner: %q, name: %q) {%s}\n", i, a.Owner, a.Repo, repoFields)
+	}
+	b.WriteString("}\n")
+
+	body, err := json.Marshal(map[string]string{"query": b.String()})
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", "https://api.github.com/graphql", bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", "awesome-coding-agents-updater")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	raw, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("graphql HTTP %d: %s", resp.StatusCode, raw)
+	}
+
+	var out graphQLResponse
+	if err := json.Unmarshal(raw, &out); err != nil {
+		return nil, fmt.Errorf("decode response: %w (body=%s)", err, raw)
+	}
+	for _, e := range out.Errors {
+		// repos that 404 or are renamed land here; continue with partial data
+		fmt.Fprintf(os.Stderr, "graphql warn: %s (path=%v)\n", e.Message, e.Path)
+	}
+
+	stats := make([]Stat, 0, len(agents))
+	for i, a := range agents {
+		node := out.Data[fmt.Sprintf("r%d", i)]
+		if node == nil {
+			fmt.Fprintf(os.Stderr, "skip %s/%s — no data\n", a.Owner, a.Repo)
+			continue
+		}
+		lang := ""
+		if node.PrimaryLanguage != nil {
+			lang = node.PrimaryLanguage.Name
+		}
+		stats = append(stats, Stat{
+			Owner:         a.Owner,
+			Repo:          a.Repo,
+			Category:      a.Category,
+			Notes:         a.Notes,
+			Description:   node.Description,
+			Stars:         node.StargazerCount,
+			Language:      lang,
+			PushedAt:      node.PushedAt,
+			URL:           node.URL,
+			NameWithOwner: node.NameWithOwner,
+		})
+	}
+	return stats, nil
+}
+
+func sortByStars(stats []Stat) {
+	sort.SliceStable(stats, func(i, j int) bool {
+		return stats[i].Stars > stats[j].Stars
+	})
+}