refactor: rename muse → talent project-wide
Three-case rename (muse/Muse/MUSE → talent/Talent/TALENT) across all
directories, filenames, Python code, CLI flags, config, docs, and tests.
Backward-compat shims for legacy journal data:
- Token logs: normalize "muse.*" context strings to "talent.*" at read time
- Exchanges: accept both "talent" and "muse" field names when reading