[Bug]: Manually rewriting an AI-generated file is incorrectly attributed to AI (0% human authorship)

[adanisman]

What broke?

Manually rewriting an AI-generated file is incorrectly attributed to AI (0% human authorship)

Steps to reproduce

Steps to Reproduce:

1. Generate a new file entirely using AI.
2. Delete the entire content of that file.
3. Manually write new code into the same file (human intervention).
4. Run git-ai and check the authorship metrics.

Expected vs actual behavior

Expected Behavior:
Since the AI-generated code was deleted and the new code was written entirely by a human, git-ai should credit the new lines to human authorship. The metric should ideally show 100% Human (or reflect the exact proportion of the new manual lines).

Actual Behavior:
git-ai still tracks the file as AI-generated. It reports 0% human contribution, even though the current code inside the file was completely written by a human.

Diagnostics (git-ai debug)

git-ai debug report
Generated (UTC): 2026-03-17T08:58:44.373063300+00:00

== Versions ==
Git AI version: 1.1.13
Git AI binary: C:\Users\tcabdanisman\.git-ai\bin\git-ai.exe
Git binary path: C:\Program Files\Git\cmd\git.exe
Git version: git version 2.53.0.windows.1

== Platform ==
OS family: windows
OS: windows
Arch: x86_64
Kernel: Microsoft Windows [Version 10.0.22631.6783]
Hostname: TT04876561
Shell: C:\WINDOWS\system32\cmd.exe
Current dir: D:\Dev\GIT-AI-TCELL\git-ai

== Hardware ==
CPU: AMD Ryzen 7 PRO 5850U with Radeon Graphics
Physical cores: 8
Logical cores: 16
Memory: 14.83 GB (15919931392 bytes)

== Repository ==
In repository: true
Workdir: D:/Dev/GIT-AI-TCELL/git-ai
Git dir: D:\Dev\GIT-AI-TCELL\git-ai\.git
Git common dir: D:\Dev\GIT-AI-TCELL\git-ai\.git
Branch: master
HEAD: cf68062253599a06f43143da43e992b1c22e93f3
Remotes:
  origin = https://stash.turkcell.com.tr/git/scm/dev1234/git-ai.git

== Git Config ==
Command: C:\Program Files\Git\cmd\git.exe config --list --show-origin --show-scope
  system        file:C:/Program Files/Git/etc/gitconfig diff.astextplain.textconv=astextplain
  system        file:C:/Program Files/Git/etc/gitconfig filter.lfs.clean=git-lfs clean -- %f
  system        file:C:/Program Files/Git/etc/gitconfig filter.lfs.smudge=git-lfs smudge -- %f
  system        file:C:/Program Files/Git/etc/gitconfig filter.lfs.process=git-lfs filter-process
  system        file:C:/Program Files/Git/etc/gitconfig filter.lfs.required=true
  system        file:C:/Program Files/Git/etc/gitconfig http.sslbackend=schannel
  system        file:C:/Program Files/Git/etc/gitconfig core.autocrlf=true
  system        file:C:/Program Files/Git/etc/gitconfig core.fscache=true
  system        file:C:/Program Files/Git/etc/gitconfig core.symlinks=false
  system        file:C:/Program Files/Git/etc/gitconfig pull.rebase=false
  system        file:C:/Program Files/Git/etc/gitconfig credential.helper=manager
  system        file:C:/Program Files/Git/etc/gitconfig credential.https://dev.azure.com.usehttppath=true
  system        file:C:/Program Files/Git/etc/gitconfig init.defaultbranch=master
  global        file:C:/Users/tcabdanisman/.gitconfig   credential.https://stash.turkcell.com.tr.provider=generic
  global        file:C:/Users/tcabdanisman/.gitconfig   user.name=tcsastan
  global        file:C:/Users/tcabdanisman/.gitconfig   user.email=mert.astan@turkcell.com.tr
  global        file:C:/Users/tcabdanisman/.gitconfig   core.compression=0
  global        file:C:/Users/tcabdanisman/.gitconfig   core.longpaths=true
  global        file:C:/Users/tcabdanisman/.gitconfig   core.editor="d:\Microsoft VS Code\bin\code" --wait
  global        file:C:/Users/tcabdanisman/.gitconfig   credential.https://stash-test.turkcell.com.tr.provider=generic
  global        file:C:/Users/tcabdanisman/.gitconfig   filter.lfs.clean=git-lfs clean -- %f
  global        file:C:/Users/tcabdanisman/.gitconfig   filter.lfs.smudge=git-lfs smudge -- %f
  global        file:C:/Users/tcabdanisman/.gitconfig   filter.lfs.process=git-lfs filter-process
  global        file:C:/Users/tcabdanisman/.gitconfig   filter.lfs.required=true
  global        file:C:/Users/tcabdanisman/.gitconfig   http.sslverify=false
  global        file:C:/Users/tcabdanisman/.gitconfig   safe.directory=*
  global        file:C:/Users/tcabdanisman/.gitconfig   safe.directory=*
  global        file:C:/Users/tcabdanisman/.gitconfig   safe.directory=*
  local file:.git/config        core.repositoryformatversion=0
  local file:.git/config        core.filemode=false
  local file:.git/config        core.bare=false
  local file:.git/config        core.logallrefupdates=true
  local file:.git/config        core.symlinks=false
  local file:.git/config        core.ignorecase=true
  local file:.git/config        remote.origin.url=https://stash.turkcell.com.tr/git/scm/dev1234/git-ai.git
  local file:.git/config        remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
  local file:.git/config        branch.master.remote=origin
  local file:.git/config        branch.master.merge=refs/heads/master

== Git AI Config ==
  config_file_path: C:\Users\tcabdanisman\.git-ai\config.json
  git_ai_dir: C:\Users\tcabdanisman\.git-ai
  runtime_config:
    {
      "git_path": "C:\\Program Files\\Git\\cmd\\git.exe",
      "exclude_prompts_in_repositories": [],
      "include_prompts_in_repositories": [],
      "allow_repositories": [],
      "exclude_repositories": [],
      "telemetry_oss_disabled": false,
      "telemetry_enterprise_dsn": null,
      "disable_version_checks": true,
      "disable_auto_updates": true,
      "update_channel": "latest",
      "feature_flags": {
        "rewrite_stash": false,
        "inter_commit_move": false,
        "auth_keyring": false,
        "git_hooks_enabled": false,
        "git_hooks_externally_managed": false
      },
      "api_base_url": "https://usegitai.com",
      "prompt_storage": "default",
      "default_prompt_storage": null,
      "api_key": null,
      "quiet": false,
      "custom_attributes": {}
    }

== Git AI Login ==
Credential backend: file
Status: logged out

== Git AI Environment ==
No GIT_AI_* environment variables are set.

Extra context (optional)