v1.5.1

Fixed

• Ext4T layout planner no longer schedules rename_or_move /
  rename_to_canonical when a basename is a name-conflict (same name,
  different content) or when another action already claims the destination
  path, so executing a plan cannot clobber a distinct package.
• Ext4T preferred_location classifies axquant/logs and axquant/scripts
  before name heuristics (smoke/tmp/candidate), and host_local also
  follows the source logs category, so operational log trees stay
  non-fleet-synced and non-deleteable.
• Ext4T package indexing skips package-root symlinks (and marks a direct
  symlink fingerprint incomplete) so content hashing cannot collide with
  the real tree and schedule deleting the target while keeping a dangling
  link.
• Coding-suite and general-holdout overlap now use
  axquant-token-5gram-v2 (same CJK-aware tokenization as
  campaign-overlap), so pure non-ASCII records no longer collapse to
  empty strings and false-positive exact matches. Coding suite manifests
  must be regenerated.
• GPTQ column encoding uses the joint round(w/s + z) form shared with
  AWQ/portable affine (fixes banker's-rounding half-integer disagreements
  with round(w/s)+z), and the standalone GPTQ plugin packs codes at
  float16 storage scale.