v0.5.0 — CSV encoding & delimiter

CSV encoding and delimiter controls. A CSV source can now be a mapping instead of a bare path, so files that aren't comma-separated utf-8 read correctly:

sources:
  sales:
    path: data/satis.csv
    encoding: cp1254      # default: utf-8-sig
    delimiter: ";"        # default: ","

The motivating case is Turkish Excel exports — frequently ;-separated, encoded cp1254, and carrying a BOM.

• Default encoding is now utf-8-sig: it reads plain utf-8 and strips the BOM Excel writes, which otherwise poisons the first column name. Backward-compatible — existing utf-8 files keep working.
• A wrong encoding fails loudly, naming the likely culprit, instead of silently mojibaking your column names and then "verifying" them.
• encoding/delimiter are validated at parse time, accepted only for .csv sources, and noted in the honesty block only when set explicitly.

Roadmap trimmed — the MCP server and these CSV controls both shipped; JSON/JSONL sources and row-level diff are next.

Full changelog: https://github.com/gulmezeren2-byte/andon/blob/main/CHANGELOG.md