🐛 Bug: File system can only store executable?: boolean, not mode?: number (Git is lossy)

[JoshuaKGoldberg]

Bug Report Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have searched for related issues and found none that matched my issue.

Expected

The diffCreatedDirectory / intakeFromDirectory system added in #129 should be consistent across computers and OSs. If tests pass locally on, say macOS, they should pass in GHA on Linux.

Actual

I'm seeing in JoshuaKGoldberg/create-typescript-app#1839 that file permissions are different after the git clone on a different OS:

FAIL  src/integration.test.ts > Producing the everything preset matches the files in this repository
Error: Snapshot `Producing the everything preset matches the files in this repository 1` mismatched

- Expected
+ Received

@@ -17,6 +17,19 @@
   
   on:
  ",
      },
    },
+   ".husky": {
+     "pre-commit": [
+       undefined,
+       {
+         "mode": "@@ -1,1 +1,1 @@
+ -81ed
+ \ No newline at end of file
+ +[81](https://github.com/JoshuaKGoldberg/create-typescript-app/actions/runs/12791420171/job/35659497983?pr=1839#step:4:82)ff
+ \ No newline at end of file
+ ",
+       },
+     ],
+   },
  }

I did some digging and learned that version control by design can't save much more than "is this file executable?" thanks to https://www.reddit.com/r/git/comments/cc7tin/does_git_not_retain_file_permission_data. Which is really the only piece I actually cared about in templating: whether a file's permissions should be elevated to executable, such as for a .husky/pre-commit file. This is fine.

Additional Info

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