Slice 10: create_pr (open a pull request)

forge CreatePullRequest (Gitea; empty base resolves to the repo default branch). Service CreatePR records a pr-created event. HTTP POST /api/repo/pr/create; MCP tool create_pr; <pr-list> New pull request button (head = selected repo current branch, base = default). Live-tested end-to-end: app create_pr opened a real PR (base auto-resolved), listed, then cleaned up; main untouched.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cmd/server/main.go

@@ -240,6 +240,23 @@ func main() {
 		}
 		return c.JSON(http.StatusOK, map[string]any{"supported": true, "prs": prs})
 	})
+	e.POST("/api/repo/pr/create", func(c echo.Context) error {
+		var body struct {
+			Path  string `json:"path"`
+			Head  string `json:"head"`
+			Base  string `json:"base"`
+			Title string `json:"title"`
+			Body  string `json:"body"`
+		}
+		if err := c.Bind(&body); err != nil {
+			return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid body"})
+		}
+		pr, err := svc.CreatePR(c.Request().Context(), activity.ActorUser, body.Path, body.Head, body.Base, body.Title, body.Body)
+		if err != nil {
+			return c.JSON(http.StatusBadGateway, map[string]string{"error": err.Error()})
+		}
+		return c.JSON(http.StatusOK, pr)
+	})
 	e.POST("/api/repo/pr/merge", func(c echo.Context) error {
 		var body struct {
 			Path   string `json:"path"`