fix(cli): clean error (not a traceback) when run outside a rendered project

[eduralph]

Summary

Closes #92. Running the console script from a directory with no pdca.toml raised an uncaught FileNotFoundError — the user saw a full Python traceback that reads like a crash (seen contributing into the Wyrd instance; works from wyrd-pdca/, not its parent):

Traceback (most recent call last):
  ...
  File ".../config.py", line 234, in _find_root
    raise FileNotFoundError("no pdca.toml found at or above … — run inside a rendered project")
FileNotFoundError: no pdca.toml found at or above /home/eddie/wyrd/wyrd — run inside a rendered project

The message was already helpful; only the surfacing was wrong.

Fix

cli.main() wraps Config.load():

• FileNotFoundError → print its message (no pdca.toml found … — run inside a rendered project), exit 2.
• malformed pdca.toml (ValueError / tomllib) → pdca: invalid pdca.toml — …, exit 2.

No traceback either way. --help and a valid in-project run are unchanged. Template-side, so every instance (gramps included) gets it on the next copier update.

Verification

• Offline suite green: 154 tests OK — new CliSurface.test_no_pdca_toml_is_clean_error_not_traceback (outside a project, status exits 2 with one clean line, no Traceback).
• Manual repro from /tmp: prints the one-line message, exit=2.

🤖 Generated with Claude Code