v0.4.0

The pack was never being read. Measured across ten sessions where the routing
line was loaded, the number that actually opened the pack file was zero. A rule
that depends on the model choosing to read a rule is not in force.

Added

• castra-posture.py, a SessionStart hook that prints the whole pack into
  context. No matcher, so it also fires after a compaction — which replaces
  earlier context with a summary and would otherwise drop the posture entirely.
• The three commands the model has to call by hand (checkpoint, guardian,
  open-loop entry) are printed alongside the pack. Their call rate was also zero
  while they lived only in a referenced file.
• Posture check that fails if any pack section is missing from the hook output,
  so a summary can never quietly replace the pack.

Changed

• The harness is now four hooks rather than three, and the CLAUDE.md routing
  line says the pack is injected rather than telling the model to open it.

Cost

About 8,600 tokens per session. A summary would be cheaper and a summary is
exactly what was already in place while nothing read the pack.