[Crane: crane-migration-python-to-go-full-apm-cli-rewrite] Iteration 147: fix mcp install probe parity (revert iter146 name-collection regression)

Root cause of PYTHON_CLI_CONTRACT_STATUS=1:

iter146 changed runMCPInstall to accept dash-prefixed args as NAME
and emit an install-context 4-line error. This contradicts the lesson
from iter143: Python Click ignore_unknown_options=True routes --X args
to ctx.args (not to the NAME positional), so Python outputs the 2-line
'Error: Missing argument NAME.' format.

Fix: restore the dash-prefix filter (iter143 behavior) and keep the
'Try ...' line added in iter146. The if startsWith(name, '-') block
is removed since it is unreachable after the filter.

errcli.go is unchanged -- iter146's fix there (removing wrong-quote
transform) was correct and remains.

Run: https://github.com/githubnext/apm/actions/runs/28274189929

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

Author: github-actions[bot]

cmd/apm/cmd_mcp.go

@@ -83,10 +83,9 @@ func runMCPInstall(args []string) int {
 		case "--limit":
 			i++ // skip value
 		default:
-			// Mirror Python Click ignore_unknown_options=True: any non-flag arg
-			// (including dash-prefixed) is accepted as NAME positional, just as
-			// Click assigns it to ctx.args and then to the NAME argument.
-			if !startsWith(a, "--limit=") && name == "" {
+			// Python Click ignore_unknown_options=True puts --X args into ctx.args,
+			// not into the NAME positional. Only non-dash args are positional.
+			if !startsWith(a, "--limit=") && !startsWith(a, "-") && name == "" {
 				name = a
 			}
 		}
@@ -96,15 +95,6 @@ func runMCPInstall(args []string) int {
 		fmt.Fprintln(os.Stderr, "Try 'apm mcp install --help' for help.")
 		return 2
 	}
-	// Python forwards: cli.main(["install", "--mcp", name, ...], standalone_mode=False)
-	// When name starts with '-', apm install rejects it as an unknown option.
-	// Mirror that: emit the install-context unknown-option error so errcli.go
-	// produces the same 4-line format Python Click generates.
-	if startsWith(name, "-") {
-		fmt.Fprintf(os.Stderr, "Error: No such option: %s\n", name)
-		fmt.Fprintln(os.Stderr, "Try 'apm install --help' for help.")
-		return 2
-	}
 
 	cwd, _ := os.Getwd()
 	ymlPath, err := findApmYML(cwd)