BigBrain v1.0.1

Fixed

• Restored page writes for registered legacy Brains that do not yet have a
  page-schemas.yaml registry. Owning MCP services now apply an atomic,
  versioned, additive compatibility migration before serving requests. The
  migration derives permissive categories from each Brain's schema_dirs,
  preserves Brain-local definitions, and never rewrites invalid or newer
  registries.

Agent update actions

• Restart each owning MCP service after installing this update. On startup the
  service creates or advances the Brain-local page schema registry when safe.
  Do not copy a registry between Brains. Review schemas/list, then verify one
  normal page create and read-back through that Brain's MCP.
• Source installations should update to v1.0.1, run npm install and
  npm link, then restart only source-managed local services. Server-managed
  deployments should promote the immutable v1.0.1 image and verify /ready
  plus authenticated tools/list after rollout.

Verification

• Focused page schema, page operation, hosted runtime, and MCP tests pass,
  including missing-registry writes by a non-admin creator, additive custom
  categories, idempotence, invalid-registry rejection, and future-version
  no-rewrite coverage.
• Full test suite passed: 684 tests passed, 7 PostgreSQL integration tests were
  skipped because TEST_DATABASE_URL was not configured, and 0 failed.
• Dashboard production build and standalone MCP bundle verification passed.