Add install/uninstall safety check via --signature flag

Automated-By: Claude Sonnet 4.6

Sources/CodeMapper/main.swift

@@ -1,12 +1,15 @@
 import Foundation
 import ArgumentParser
 
+let buildSignature = "CODEMAPPER-SIGNATURE-izackp"
+
 struct CodeMapper: ParsableCommand {
     static let configuration = CommandConfiguration(
         commandName: "CodeMapper",
         abstract: "Generate LLM-friendly architectural maps from Swift source files."
     )
 
+
     @Option(name: .long, help: "Root of the Swift package to analyze.")
     var sources: String
 
@@ -103,4 +106,10 @@ struct CodeMapper: ParsableCommand {
 
 // Ignore SIGPIPE so LSP subprocess death returns an error instead of killing this process
 signal(SIGPIPE, SIG_IGN)
+
+if CommandLine.arguments.contains("--signature") {
+    print(buildSignature)
+    exit(0)
+}
+
 CodeMapper.main()