feat(pr): add +commits and +check-merge

- pr +commits: list commits of a pull request
  (GET /pulls/:id/commits)
- pr +check-merge: pre-flight check_can_merge before creating a PR.
  Detects same-branch no-ops and existing duplicate merge requests,
  including the cross-fork case via --fork-project-id (which also
  sets is_original, matching the server's duplicate lookup).

Production-verified on gitlink.org.cn: commits listing, a
'can merge' pass, and duplicate detection that points at the
existing PR. 2 unit tests, README examples, bilingual i18n keys.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

README.md

@@ -420,6 +420,14 @@ gitlink-cli pr +reopen --owner Gitlink --repo forgeplus -i 42
 # View changed files
 gitlink-cli pr +files --owner Gitlink --repo forgeplus -i 42
 
+# List commits of a pull request
+gitlink-cli pr +commits --owner Gitlink --repo forgeplus -i 42
+
+# Pre-flight: can a merge request be created between two branches?
+gitlink-cli pr +check-merge --owner Gitlink --repo forgeplus --head develop --base master
+# Cross-fork variant
+gitlink-cli pr +check-merge --owner Gitlink --repo forgeplus --head feat/x --base master --fork-project-id 12345
+
 # List PR patchset versions
 gitlink-cli pr +versions --owner Gitlink --repo forgeplus -i 42
 

internal/i18n/locales/en-US.json

@@ -52,8 +52,10 @@
   "cmd.org.list.short": "List organizations",
   "cmd.org.members.short": "List organization members",
   "cmd.org.short": "Organization operations",
+  "cmd.pr.check_merge.short": "Pre-flight check whether a merge request can be created between two branches",
   "cmd.pr.close.short": "Close a pull request",
   "cmd.pr.comment.short": "Add a comment to a pull request",
+  "cmd.pr.commits.short": "List commits of a pull request",
   "cmd.pr.create.short": "Create a pull request",
   "cmd.pr.diff.short": "Show diff for a pull request",
   "cmd.pr.files.short": "List changed files in a pull request",
@@ -182,6 +184,7 @@
   "flag.pr.base": "Target branch",
   "flag.pr.body": "PR description",
   "flag.pr.file": "Filter diff by file path",
+  "flag.pr.fork_project_id": "Fork project ID for cross-fork merge checks",
   "flag.pr.head": "Source branch",
   "flag.pr.id": "PR number",
   "flag.pr.merge_method": "Merge method: merge, rebase, squash",

internal/i18n/locales/zh-CN.json

@@ -52,8 +52,10 @@
   "cmd.org.list.short": "列出组织",
   "cmd.org.members.short": "列出组织成员",
   "cmd.org.short": "组织操作",
+  "cmd.pr.check_merge.short": "预检两个分支之间能否创建合并请求",
   "cmd.pr.close.short": "关闭拉取请求",
   "cmd.pr.comment.short": "给拉取请求添加评论",
+  "cmd.pr.commits.short": "列出合并请求的提交",
   "cmd.pr.create.short": "创建拉取请求",
   "cmd.pr.diff.short": "显示拉取请求 diff",
   "cmd.pr.files.short": "列出拉取请求中的变更文件",
@@ -182,6 +184,7 @@
   "flag.pr.base": "目标分支",
   "flag.pr.body": "PR 描述",
   "flag.pr.file": "按文件路径筛选 diff",
+  "flag.pr.fork_project_id": "跨 fork 合并检查用的 fork 项目 ID",
   "flag.pr.head": "源分支",
   "flag.pr.id": "PR 编号",
   "flag.pr.merge_method": "合并方式：merge、rebase、squash",

shortcuts/pr/pr.go

@@ -3,6 +3,7 @@ package pr
 import (
 	"fmt"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"github.com/gitlink-org/gitlink-cli/internal/i18n"
@@ -227,6 +228,57 @@ func Shortcuts(translators ...*i18n.Translator) []*common.Shortcut {
 				return ctx.Output(env)
 			},
 		},
+		{
+			Name:        "commits",
+			Description: tr.T("cmd.pr.commits.short"),
+			Flags: []common.Flag{
+				{Name: "id", Short: "i", Usage: tr.T("flag.pr.id"), Required: true},
+			},
+			Run: func(ctx *common.RuntimeContext) error {
+				if err := ctx.ResolveOwnerRepo(); err != nil {
+					return err
+				}
+				id, _ := ctx.RequireArg("id")
+				env, err := ctx.CallAPI("GET", fmt.Sprintf("%s/pulls/%s/commits", ctx.RepoPath(), id), nil)
+				if err != nil {
+					return err
+				}
+				return ctx.Output(env)
+			},
+		},
+		{
+			Name:        "check-merge",
+			Description: tr.T("cmd.pr.check_merge.short"),
+			Flags: []common.Flag{
+				{Name: "head", Usage: tr.T("flag.pr.head"), Required: true},
+				{Name: "base", Usage: tr.T("flag.pr.base"), Required: true},
+				{Name: "fork-project-id", Usage: tr.T("flag.pr.fork_project_id")},
+			},
+			Run: func(ctx *common.RuntimeContext) error {
+				if err := ctx.ResolveOwnerRepo(); err != nil {
+					return err
+				}
+				head, _ := ctx.RequireArg("head")
+				base, _ := ctx.RequireArg("base")
+				payload := map[string]interface{}{
+					"head": head,
+					"base": base,
+				}
+				if forkID := ctx.Arg("fork-project-id"); forkID != "" {
+					id, err := strconv.Atoi(forkID)
+					if err != nil {
+						return fmt.Errorf("--fork-project-id must be an integer, got %q", forkID)
+					}
+					payload["fork_project_id"] = id
+					payload["is_original"] = true
+				}
+				env, err := ctx.CallAPI("POST", ctx.RepoPath()+"/pulls/check_can_merge", payload)
+				if err != nil {
+					return err
+				}
+				return ctx.Output(env)
+			},
+		},
 		{
 			Name:        "diff",
 			Description: tr.T("cmd.pr.diff.short"),

shortcuts/pr/pr_test.go

@@ -531,3 +531,46 @@ func assertEqual(t *testing.T, got interface{}, want interface{}) {
 		t.Fatalf("got %v (%T), want %v (%T)", got, got, want, want)
 	}
 }
+
+func TestPRCommitsUsesCommitsEndpoint(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" || r.URL.Path != "/owner/repo/pulls/355/commits.json" {
+			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
+		}
+		writeJSON(t, w, map[string]interface{}{"commits_count": float64(1), "commits": []interface{}{}})
+	}))
+	defer server.Close()
+
+	if err := runPRShortcut(t, server, "commits", map[string]string{"id": "355"}); err != nil {
+		t.Fatalf("commits failed: %v", err)
+	}
+}
+
+func TestPRCheckMergePostsBranchesAndForkTuple(t *testing.T) {
+	var payload map[string]interface{}
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "POST" || r.URL.Path != "/owner/repo/pulls/check_can_merge.json" {
+			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
+		}
+		payload = decodeJSON(t, r)
+		writeJSON(t, w, map[string]interface{}{"status": float64(0), "message": "可以合并"})
+	}))
+	defer server.Close()
+
+	err := runPRShortcut(t, server, "check-merge", map[string]string{
+		"head": "feat/x", "base": "master", "fork-project-id": "1549132",
+	})
+	if err != nil {
+		t.Fatalf("check-merge failed: %v", err)
+	}
+	assertEqual(t, payload["head"], "feat/x")
+	assertEqual(t, payload["base"], "master")
+	assertEqual(t, payload["fork_project_id"], float64(1549132))
+	assertEqual(t, payload["is_original"], true)
+
+	if err := runPRShortcut(t, server, "check-merge", map[string]string{
+		"head": "a", "base": "b", "fork-project-id": "abc",
+	}); err == nil {
+		t.Fatal("expected error for non-integer --fork-project-id")
+	}
+}