v1.23.4 — agent-sync

• The guard fails silent on an Edit payload of the wrong shape (hub B-211 follow-up): a payload
  that is not an object, a tool_input that is a string, or a file_path that is not a string
  raised inside the parser, and the parser's non-zero exit failed CLOSED (exit 2) in a configured
  session. Such a payload names no file and now passes, as the apply_patch branch already did.
  Three GUARD_SHAPES rows; two of them fail on 1.23.3.
• The generated AGENT_SYNC.md carries no em dash (hub B-289): the setup snapshot's headings,
  table cells, wiring and credential lines, and the generated-file marker use a colon, semicolon
  or parentheses. The marker keeps its agent-sync:generated source=... cfg=... at=... fields;
  a project's snapshot changes on its next agent_sync.py setup.