Spine v3.56.0

What's Changed

Other changes

• feat: Spine checks requirements — openspec draft --idea / check / answer, MCP tools, clear-gate (SSPN-98) by @ssmith-synaptixs in #519
• fix(sdlc): retry malformed structured codegen responses (SSPN-127, B57) by @ssmith-synaptixs in #520
• chore(release): cut 3.56.0 by @ssmith-synaptixs in #521
• fix(plugin): break the requirements_tools <-> server import cycle (SSPN-128, B58) by @ssmith-synaptixs in #522
• Release 3.56.0: promote develop to main by @ssmith-synaptixs in #523

Full Changelog: v3.55.0...v3.56.0