feat(modules/amm): add sync-reserves module op

A permissionless keeper op that refreshes a pool's stored reserves to the live
vault balances (and its TWAP tick). Same lean pattern as the other plans, but
minimal: SyncReserves is a unit instruction — no quote, no user inputs (no
amounts/slippage/deadline/holdings), and nothing signs.

FFI (modules/amm/ffi):
- sync_reserves_plan: encodes SyncReserves over the fixed 6-account IDL order
  (config, pool, vault_a, vault_b, current_tick, clock), all non-signing.
  config/pool/current_tick/clock are order-independent PDAs from derive_pair;
  the vaults come from the pool's stored ids in pool_data (read-only, but the
  guest still asserts them — a non-canonically-stored pool would otherwise
  mismatch). Fails closed: same_token_pair, config_unavailable, no_pool.
- Wired through mod.rs / ffi.rs (cbindgen header regenerated). Tests cover the
  stored-vault + zero-signer + unit-instruction layout and the fail-closed
  paths. amm_ffi: 43 tests pass, clippy clean. (lib.rs is a cargo fmt re-wrap.)

C++ module (modules/amm/src):
- syncReserves reads config + pool server-side, calls the plan, and submits.
  request is just { tokenAId, tokenBId } — no holdings/amounts/deadline. Public
  method → auto-exposed via the universal-module dispatch.

modules/amm/ffi/src/api/mod.rs

@@ -21,7 +21,8 @@ pub use request::{
     CreatePoolPlanRequest, LiquidityQuoteRequest, PairIdsRequest, PoolIdRequest, ProgramIdRequest,
     RemoveLiquidityPlanRequest, RemoveLiquidityQuoteRequest, ResolvePoolRequest,
     SwapExactInPlanRequest, SwapExactInQuoteRequest, SwapExactOutPlanRequest,
-    SwapExactOutQuoteRequest, SwapPairRequest, TokenHoldingsRequest, TokenIdsRequest,
+    SwapExactOutQuoteRequest, SwapPairRequest, SyncReservesPlanRequest, TokenHoldingsRequest,
+    TokenIdsRequest,
 };
 use serde_json::Value;
 
@@ -142,6 +143,10 @@ pub fn remove_liquidity_plan(request: RemoveLiquidityPlanRequest) -> AmmResult {
     liquidity::remove_liquidity_plan(request).map_err(Into::into)
 }
 
+pub fn sync_reserves_plan(request: SyncReservesPlanRequest) -> AmmResult {
+    liquidity::sync_reserves_plan(request).map_err(Into::into)
+}
+
 /// Lists the wallet's fungible token holdings for the account selector.
 pub fn token_holdings(request: TokenHoldingsRequest) -> AmmResult {
     token_holdings::token_holdings(request).map_err(Into::into)