Move Gitea feed from frontend to backend with cached GraphQL proxy

Replaces direct browser-to-Gitea API calls with a backend service that
proxies and caches the feed (1-min TTL), served via the existing GraphQL
HomeData query. Commit message parsing now happens server-side.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/gitea.go

@@ -0,0 +1,72 @@
+package services
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+type GiteaFeedCommit struct {
+	Message string `json:"Message"`
+}
+
+type GiteaFeedContent struct {
+	Commits []GiteaFeedCommit `json:"Commits"`
+}
+
+type GiteaFeedUser struct {
+	AvatarURL string `json:"avatar_url"`
+}
+
+type GiteaFeedRepo struct {
+	FullName string `json:"full_name"`
+	HTMLURL  string `json:"html_url"`
+}
+
+type GiteaFeedResponse struct {
+	ActUser GiteaFeedUser `json:"act_user"`
+	Repo    GiteaFeedRepo `json:"repo"`
+	OpType  string        `json:"op_type"`
+	Content string        `json:"content"`
+	Created time.Time     `json:"created"`
+}
+
+func FetchLatestFeed(host, port string) (*GiteaFeedResponse, error) {
+	url := fmt.Sprintf("http://%s:%s/api/v1/users/adamf/activities/feeds?limit=1", host, port)
+
+	client := &http.Client{Timeout: 5 * time.Second}
+	resp, err := client.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var items []GiteaFeedResponse
+	if err := json.Unmarshal(body, &items); err != nil {
+		return nil, err
+	}
+
+	if len(items) == 0 {
+		return nil, nil
+	}
+
+	return &items[0], nil
+}
+
+func ParseCommitMessage(content string) string {
+	var c GiteaFeedContent
+	if err := json.Unmarshal([]byte(content), &c); err != nil {
+		return ""
+	}
+	if len(c.Commits) == 0 {
+		return ""
+	}
+	return c.Commits[0].Message
+}