V-L1-F1: simulation semantics ADR (isolation / merge policy / conflict reporting)

[hyperpolymath]

Context

verisimdb_simulation_branches + _deltas tables exist but no semantics are documented for branch creation, merge resolution, isolation, or conflict reporting.

What to do

Write docs/theory/simulation-semantics.adoc covering: branch creation, delta isolation level, merge policy (last-writer-wins? CRDT? manual?), conflict reporting, integration with target-DB transactions.

Acceptance

• ADR pinning the chosen semantics
• Doc cites it