v1.5.1

PrimeCode v1.5.1

fix(child-cards): remove unreliable file-change counters from child sessions

OpenCode does not attribute diff/summary data per causal session owner.
Both session.summary and session.diff reflect shared worktree state
during the session's lifetime, making them misleading for child cards.

Remove the entire diffStats pipeline — type, derivation, selector, and
render — from child task cards. Token counters, timers, agent/model
badges, and depth indicators remain unchanged.

Also:

• hydrate loads session.diff for every subtree session (not just root)
• hydrate syncs session.status for the full subtree
• dump-sessions.ts rewritten for complete recursive dumps with
  raw messages, per-session diff/todo, and instance context
• removed computeSessionDiffStats() (dead code)
• fix inline Attachment