fix(logging): add optional chaining to prevent undefined property access

Add optional chaining operators to message.usage property access in console log statements to prevent potential "Cannot read property of undefined" errors when the usage object might not exist.

Author: tsdevau

src/commitMessageGenerator.ts

@@ -88,10 +88,10 @@ export class CommitMessageGenerator {
       return undefined
     } finally {
       console.log("[DiffCommit] Stop Reason: ", message?.stop_reason)
-      console.log("[DiffCommit] Input Tokens: ", message?.usage.input_tokens)
-      console.log("[DiffCommit] Cache Creation Tokens: ", message?.usage.cache_creation_input_tokens)
-      console.log("[DiffCommit] Cache Read Tokens: ", message?.usage.cache_read_input_tokens)
-      console.log("[DiffCommit] Output Tokens: ", message?.usage.output_tokens)
+      console.log("[DiffCommit] Input Tokens: ", message?.usage?.input_tokens)
+      console.log("[DiffCommit] Cache Creation Tokens: ", message?.usage?.cache_creation_input_tokens)
+      console.log("[DiffCommit] Cache Read Tokens: ", message?.usage?.cache_read_input_tokens)
+      console.log("[DiffCommit] Output Tokens: ", message?.usage?.output_tokens)
     }
   }