bigmerge
6621a4dbc5
Add the universal engram mutation as ONE operation: isolate a region (cosine + adjacency) -> supersede it as a set (immutable region-tombstone, originals retained, engram_forget never used) -> insert the new manifold as a set -> rebind edges by cosine -> one atomic persist. Single-node write and supersede are the degenerate n=1 case of the same reframe_core path, not a separate CRUD path. Keystones kn-efeb4a5b / kn-5b606390 are write-protected. Purely additive: routes POST /api/reframe, /api/write, /api/supersede. Verified on an isolated clone of the JSON-snapshot engine (set-replace, n=1, no-regression, keystones, durable reboot); compile-verified clean against the cognition multi-TU build. NOT deployed — prod :8742 frozen; blue-verify on the cognition/egm engine required before any cut.