Ports Minas's PR #172 (against pre-rename `da` CLI on main) and applies
the principle to the post-rename `agnes` CLI. Two distinct failure modes
on Windows consoles whose default codepage is cp1250 (cs-CZ) / cp1252
(en-US):
1. `agnes pull` and other Rich-progress codepaths
UnicodeEncodeError on Braille spinner glyphs. Fix: `cli/main.py`
reconfigures stdout/stderr to UTF-8 with errors='replace' at import
time on `sys.platform == 'win32'` so Rich's legacy-Windows render
path emits decodable bytes. Wrapped in try/except so pytest's
captured streams (which aren't TextIOWrapper) don't break.
2. `agnes skills list` and `agnes skills show`
UnicodeDecodeError when reading skill markdown containing em-dashes /
accented chars. Default `Path.read_text()` uses
locale.getpreferredencoding(False), which is the broken codepage on
Windows. Fix: every call site passes encoding='utf-8' explicitly.
Broader scope than #172 because:
- The bootstrap rewrite renamed/removed several files Minas's PR
patched (`cli/commands/analyst.py` -> rolled into init.py;
`cli/commands/sync.py` -> split into pull/push). Those targets no
longer exist; the equivalent code lives in init.py.
- Other call sites Minas didn't touch (still bare in his branch) are
patched here too — config.py / update_check.py / snapshot_meta.py /
setup.py / skills.py — so the codebase has zero locale-default text
I/O in cli/.
Side cleanup: stale `Run `da`` reference in snapshot_meta.py:88 fixed
to `agnes` while touching the file.
