Schedule: Add unit tests to services/github/trees/get_file_tree_list.py

[gitauto-ai]

Resolves #1974

Summary

Add comprehensive unit tests for services/github/trees/get_file_tree_list.py, targeting full line/statement/function coverage and exercising the previously uncovered conditional around line 53.

Test Patterns

• Happy path: returns expected file list for a flat tree response
• Nested directories: correct filtering and path handling for deep trees
• Empty tree: returns empty list without errors
• Invalid inputs: empty/None repo, owner, or path raise appropriate exceptions
• GitHub API errors: 4xx/5xx responses propagate as errors
• Malformed payload: missing or unexpected fields handled gracefully
• Non-file entries: directories, symlinks, and submodules processed/ignored per spec
• Large trees/pagination or recursive flag behavior (if applicable)
• Network/transport failures: timeouts or connection errors handled
• Branch coverage: tests explicitly drive both sides of the conditional at line 53

git fetch origin
git checkout gitauto/issue-1974-20251015-000101-uXSK
git pull origin gitauto/issue-1974-20251015-000101-uXSK