replace files-to-prompt with git ls-files for bloat metrics

files-to-prompt was including untracked files (knowledge/, dev scripts, etc.) which inflated the bloat metrics. now we use git ls-files to only count tracked source files, which is more accurate and removes an external dependency.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

uv.lock

@@ -341,18 +341,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/42/14/42b2651a2f46b022ccd948bca9f2d5af0fd8929c4eec235b8d6d844fbe67/filelock-3.19.1-py3-none-any.whl", hash = "sha256:d38e30481def20772f5baf097c122c3babc4fcdb7e14e57049eb9d88c6dc017d", size = 15988, upload-time = "2025-08-14T16:56:01.633Z" },
 ]
 
-[[package]]
-name = "files-to-prompt"
-version = "0.6"
-source = { registry = "https://pypi.org/simple" }
-dependencies = [
-    { name = "click" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/b9/4f/81fc86a88dc9e0cf6ea1ac2c561c0ac48b46d314cbbc2db5c8844b4b448b/files_to_prompt-0.6.tar.gz", hash = "sha256:9af57eecbdb29d3cce034c186493ffc6c1205ea4f5abde6fb32ccb1d96eae40c", size = 12236, upload-time = "2025-02-19T05:58:28.2Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/a0/99/0efff50ce810119d99eaa2fc0c7bbf66e4197e2defb89242f6e848004902/files_to_prompt-0.6-py3-none-any.whl", hash = "sha256:83d9a8b33246a10233218716a5c78034da4f5614748eda2f0ab94f1117801337", size = 10873, upload-time = "2025-02-19T05:58:26.728Z" },
-]
-
 [[package]]
 name = "frozenlist"
 version = "1.7.0"
@@ -752,7 +740,6 @@ source = { virtual = "." }
 dependencies = [
     { name = "datasets" },
     { name = "fastapi" },
-    { name = "files-to-prompt" },
     { name = "psutil" },
     { name = "regex" },
     { name = "rustbpe" },
@@ -785,7 +772,6 @@ dev = [
 requires-dist = [
     { name = "datasets", specifier = ">=4.0.0" },
     { name = "fastapi", specifier = ">=0.117.1" },
-    { name = "files-to-prompt", specifier = ">=0.6" },
     { name = "psutil", specifier = ">=7.1.0" },
     { name = "regex", specifier = ">=2025.9.1" },
     { name = "rustbpe", specifier = ">=0.1.0" },