[Crane: crane-migration-python-to-go-full-apm-cli-rewrite] Iteration 143: fix apm mcp install unknown-option parity

Changes:
- cmd/apm/cmd_mcp.go: Fix runMCPInstall to not treat --X args as NAME
  positional. Python Click's ignore_unknown_options=True treats --X as
  unknown options (ctx.args), not as NAME. So 'apm mcp install --foo'
  outputs 'Error: Missing argument NAME.' -- not the 4-line UsageError.
- Remove unreachable strings.HasPrefix(name, "-") error block.

Run: https://github.com/githubnext/apm/actions/runs/28225237618

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

cmd/apm/cmd_mcp.go

@@ -83,9 +83,10 @@ func runMCPInstall(args []string) int {
 		case "--limit":
 			i++ // skip value
 		default:
-			if !startsWith(a, "--limit=") && name == "" {
-				// Mirror Python's ignore_unknown_options=True: treat any
-				// unrecognised arg (including --X) as the NAME positional.
+			// Mirror Python Click: args starting with '-' are unknown options
+			// (they go to ctx.args via ignore_unknown_options=True and never
+			// fill the NAME positional). Only non-dash args are positional.
+			if !startsWith(a, "--limit=") && !startsWith(a, "-") && name == "" {
 				name = a
 			}
 		}
@@ -94,15 +95,6 @@ func runMCPInstall(args []string) int {
 		fmt.Fprintln(os.Stderr, "Error: Missing argument 'NAME'.")
 		return 2
 	}
-	// Python's build_mcp_entry() raises ValueError for names that fail the MCP
-	// name regex; Click converts it to UsageError and prints 4 lines to stderr.
-	if strings.HasPrefix(name, "-") {
-		fmt.Fprintln(os.Stderr, "Usage: apm mcp install [OPTIONS] NAME")
-		fmt.Fprintln(os.Stderr, "Try 'apm mcp install --help' for help.")
-		fmt.Fprintln(os.Stderr, "")
-		fmt.Fprintf(os.Stderr, "Error: Invalid MCP dependency name '%s': must start with a letter, digit, '@', or '_' and contain only [a-zA-Z0-9._@/:=-] (max 128 chars). Example: 'io.github.acme/cool-server' or 'my-server'.\n", name)
-		return 2
-	}
 
 	cwd, _ := os.Getwd()
 	ymlPath, err := findApmYML(cwd)