fix: Numeric book titles (1984, 2001) classified as garbage by folder triage

[deucebucket]

Bug

In `folder_triage.py` (~line 37), the garbage pattern `r'^[\d\s\-\.]+$'` classifies all-numeric folder names as garbage. Folders named "1984", "2001", or "11-22-63" (real book titles) are classified as garbage, causing path data to be discarded with a -10 confidence penalty.

`book_profile.py` already has a `famous_numeric` set for this exact case in `is_valid_title()`, but `folder_triage.py` has no such exception.

Fix

Add a `FAMOUS_NUMERIC` exception set to `triage_folder()`, matching the one in `book_profile.py`.

Severity

Medium — well-known books with numeric titles get worse identification.

Found via pipeline logic audit.

[deucebucket]

Implemented on main by commit 6fbf68a: known numeric book titles are exempted from the folder-triage garbage rule.