v3.12.2

Antigravity permissions-adapter repair.

• Consumes Antigravity's native nested toolCall payload and emits native top-level allow/deny decisions.
• Normalizes command, file, multi-edit, and MCP calls into Signet's existing canonical policy model.
• Makes native MCP wrapper identity authoritative, rejects spoofed identity fields, and fails closed on malformed wrappers.
• Ships an Antigravity hook configuration plus README and project-site setup documentation.
• Aligns Cargo, Kindex, MCP Registry, and Claude plugin metadata on v3.12.2.
• Passes 231 tests, formatting, lint, crate packaging, and crates.io publish dry-run verification.