add seed registry, tag vocabulary (measure/seed/program), and Zotero library cleanup
- Tag.measure(), Tag.seed(), Tag.program() factory methods
- dev/scripts/register_seeds.py: declarative registry mapping 34 seed
files to source URLs, titles, and tags with bidirectional Zotero sync
- Zotero library standardization: authors on 2451/2504 items, CFR titles
from eCFR API (630 sections with headings, 15 cross-title corrections),
1070 URL-as-title items resolved to real page titles
- openpyxl + pdfplumber dev deps for seed file inspection
421ce48fd8
