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/label/label.go

@@ -47,6 +47,7 @@ var (
 		mcp.WithString("color", mcp.Description("label color hex code e.g. #RRGGBB (required for create, optional for edit)")),
 		mcp.WithString("description", mcp.Description("label description")),
 		mcp.WithBoolean("exclusive", mcp.Description("whether the label is exclusive (org labels only)")),
+		mcp.WithBoolean("is_archived", mcp.Description("whether the label is archived (for create/edit repo label methods)")),
 	)
 )
 
@@ -178,10 +179,13 @@ func createRepoLabelFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallT
 	}
 	description, _ := req.GetArguments()["description"].(string) // Optional
 
+	isArchived, _ := req.GetArguments()["is_archived"].(bool)
+
 	opt := gitea_sdk.CreateLabelOption{
 		Name:        name,
 		Color:       color,
 		Description: description,
+		IsArchived:  isArchived,
 	}
 
 	client, err := gitea.ClientFromContext(ctx)
@@ -220,6 +224,9 @@ func editRepoLabelFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToo
 	if description, ok := req.GetArguments()["description"].(string); ok {
 		opt.Description = new(description)
 	}
+	if isArchived, ok := req.GetArguments()["is_archived"].(bool); ok {
+		opt.IsArchived = &isArchived
+	}
 
 	client, err := gitea.ClientFromContext(ctx)
 	if err != nil {