Drop Julia, assign one primary language per M3 sim spec

Ranked languages per spec by fit; took only the top pick:
- M3a (statistical): R — native stats ecosystem
- M3b (sociological): Prolog — equilibria as constraint satisfaction
- M3c (AMM): Solidity — on-chain-equivalent precision
- M3d (MEV): Fortran — dense PDE/knapsack numerics, no GC
- M3e (tokenomics): Fortran — SDE/VAR matrix loops, same toolchain as M3d
- M3f (consensus): Prolog — Markov/Nash as declarative search
- M3g (microstructure): Zig — tick-level latency, deterministic memory
- Hub: updated to reflect per-spec assignments

Julia removed project-wide: JIT startup cost and large toolchain
not justified when the project isn't going all-in on a single runtime.

core/docs/plans/M3f-consensus-staking-sims.md

@@ -14,8 +14,10 @@ validator populations C4 (Lasry & Lions 2007; validator-specific application C3)
 simulation parameterization C1.
 
 ## 3. Language & location
-TBD · `src/economy/sims/consensus/`. Needs Markov chain solvers and game-theoretic equilibrium
-computation. Julia, R, or Fortran.
+TBD · `src/economy/sims/consensus/`. **Prolog** — Markov chain transition rules, Nash
+equilibrium search, and replicator dynamics are constraint-satisfaction problems over validator
+populations; Prolog's backtracking search finds equilibria declaratively rather than
+imperatively iterating toward them.
 
 ## 4. Does / does-not
 - **Does:** simulate validator populations where honesty evolves via **evolutionary game theory**