Move uploaded files from workspace to DATA_DIR for consistency with history/memory

[dcellison]

Summary

_save_to_workspace() in bot.py saves user-uploaded files to workspace/files/ (the inner Claude working directory). Meanwhile, _apply_directories() in install.py creates an empty /var/lib/kai/files/ that nothing uses.

This is the same category of issue PR #144 fixed for history and MEMORY.md: runtime data living inside the install tree instead of DATA_DIR.

Current state

• Where files are saved: pool.get_workspace(chat_id) / "files/" (resolves to /opt/kai/workspace/files/ in production)
• Where _apply_directories creates a directory: DATA_DIR / "files" (resolves to /var/lib/kai/files/)
• Result: /var/lib/kai/files/ exists but is always empty. Uploaded files live in the install tree.

Why it matters

• The merge-based _copy_tree (PR Move runtime data (history, memory) out of install tree #144) protects these files from deletion on install, but they are still inside the install tree where they do not belong
• _apply_directories creates an unused directory, which is misleading
• The inner Claude accesses files by workspace-relative path, so moving them requires injecting the absolute path into context (same pattern as the history directory fix in PR Move runtime data (history, memory) out of install tree #144)

Proposed fix

Follow the PR #144 pattern:

1. Move file storage from workspace/files/ to DATA_DIR / "files" (which already exists)
2. Update _save_to_workspace() to save to DATA_DIR / "files" instead of workspace / "files"
3. Inject the absolute files path into context so the inner Claude knows where to find them
4. Add a migration in _apply_migrate for any existing files at the old location
5. Add "files" to .gitignore for the dev layout (if not already covered)

Priority

Low. The merge-based _copy_tree prevents data loss. This is a cleanup for architectural consistency with the history/memory fix.

[dcellison]

Triage by Kai

Triage summary: Architectural cleanup to move uploaded file storage from workspace/files/ (inside the install tree) to DATA_DIR/files/, following the same pattern PR #144 applied to history and MEMORY.md. No data loss risk exists currently, but the current layout is inconsistent and leaves an unused directory.

Priority: low
Labels applied: enhancement, good first issue
Added to project: Code Review - March 2026