Add missing tool parameters from Gitea SDK (#164)

Expose additional parameters that the Gitea SDK supports but were not yet wired through the MCP tool definitions.

**Motivation:** Systematic comparison against github-mcp-server and the Gitea SDK revealed several supported parameters that were missing from tool schemas.

- `list_issues`: `labels`, `since`, `before` filters
- `issue_write`: `labels` and `deadline` on create, `deadline`/`remove_deadline` on update
- `pull_request_write`: `labels`/`deadline` on create/update, `remove_deadline` on update, `force_merge`/`merge_when_checks_succeed`/`head_commit_id` on merge
- `list_branches`: `page`/`perPage` pagination
- `create_repo`: `trust_model`, `object_format_name`
- `label_write`: `is_archived` on create/edit

**Testing:** Added tests for issue list filters, issue create labels/deadline, PR create labels/deadline, and PR merge new params.

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/164
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

operation/repo/branch.go

@@ -43,6 +43,8 @@ var (
 		mcp.WithDescription("List branches"),
 		mcp.WithString("owner", mcp.Required(), mcp.Description("repository owner")),
 		mcp.WithString("repo", mcp.Required(), mcp.Description("repository name")),
+		mcp.WithNumber("page", mcp.Description("page number"), mcp.DefaultNumber(1)),
+		mcp.WithNumber("perPage", mcp.Description("results per page"), mcp.DefaultNumber(30)),
 	)
 )
 
@@ -131,10 +133,11 @@ func ListBranchesFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallTool
 	if err != nil {
 		return to.ErrorResult(err)
 	}
+	page, pageSize := params.GetPagination(args, 30)
 	opt := gitea_sdk.ListRepoBranchesOptions{
 		ListOptions: gitea_sdk.ListOptions{
-			Page:     1,
-			PageSize: 30,
+			Page:     page,
+			PageSize: pageSize,
 		},
 	}
 	client, err := gitea.ClientFromContext(ctx)