v0.23.3

mv now migrates nested project sessions and rewrites githubRepoPaths

Context

mv previously matched only the exact moved path: session data for projects nested
inside a moved directory was silently left stale (requiring manual per-child
--post-hoc runs), and githubRepoPaths values were never rewritten for any move.
mv is now prefix-aware over real decoded paths, verifies every descendant's
destination before touching anything, and hard-errors on ambiguous encoded names.

Fixes

• mv now migrates nested projects. Moving a directory that contains other Claude Code project dirs migrates every descendant's session data (encoded project dirs, .claude.json project keys, JSONL cwd references) and rewrites githubRepoPaths entries pointing into the moved tree. Undecodable or ambiguous encoded dirs and missing descendant destinations abort the move before anything is touched.