docs: Add subsystem AGENTS.md files for transactors, ledger helpers, and READMEs

Round 2 of PR-review mining: found two subsystem-specific, unrecorded
conventions (pseudo-account auth/freeze exemption in vault/lending
transactors; SLE-type assertion in ledger helpers) that warrant their
own nested AGENTS.md rather than more root-level bullets.

Also added thin AGENTS.md pointer files (with CLAUDE.md symlinks,
matching the existing convention) for subsystems that already have a
substantial README.md but no AGENTS.md — agent tooling auto-loads
AGENTS.md when working in a directory but not README.md, so those
conventions were otherwise invisible to an agent that didn't think to
look.

include/xrpl/consensus/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — consensus
+
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general guidance. See [README.md](./README.md) for a short pointer, and [docs/consensus.md](../../../docs/consensus.md) for the full consensus design.

include/xrpl/consensus/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

include/xrpl/nodestore/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — nodestore
+
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general guidance and [README.md](./README.md) for backend and benchmark design.

include/xrpl/nodestore/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

include/xrpl/shamap/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — shamap
+
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general guidance and [README.md](./README.md) for the SHAMap design.

include/xrpl/shamap/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/libxrpl/ledger/helpers/AGENTS.md

@@ -0,0 +1,5 @@
+# AGENTS.md — ledger/helpers
+
+See the repo-level [AGENTS.md](../../../../AGENTS.md) for general guidance.
+
+A helper that takes an `SLE`/`std::shared_ptr<SLE const>` should `XRPL_ASSERT` that it's non-null and of the expected ledger-entry type at entry, and keep a real runtime check/error-return alongside the assert (asserts compile out in release builds). Don't invent a new error-handling idiom for this (e.g. `std::unexpected`) — return the existing `tec`/`ter`/`tef` code used elsewhere in the codebase.

src/libxrpl/ledger/helpers/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/libxrpl/tx/transactors/AGENTS.md

@@ -0,0 +1,7 @@
+# AGENTS.md — transactors
+
+See [tx/AGENTS.md](../AGENTS.md) for amendment-gating conventions that apply to all transactors, and the repo-level [AGENTS.md](../../../../AGENTS.md) for general guidance.
+
+Pseudo-accounts (Vault, LoanBroker, AMM, ...) are exempt from `requireAuth` and freeze/deep-freeze checks as a class, not on a per-asset-type basis. Code that touches a pseudo-account (deposits, withdrawals, clawback, deletion, credential checks) must preserve that exemption rather than re-deriving it for each asset type.
+
+Prefer a single object-level invariant over duplicating the same delta/balance check in every transactor that touches an object — e.g. one invariant asserting a Vault's pseudo-account balance and `assetsAvailable` always move together, rather than repeating that check in `VaultDeposit`, `VaultWithdraw`, `VaultClawback`, `LoanSet`, etc.

src/libxrpl/tx/transactors/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/xrpld/app/consensus/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — consensus
+
+See the repo-level [AGENTS.md](../../../../AGENTS.md) for general guidance. See [README.md](./README.md) for a short pointer, and [docs/consensus.md](../../../../docs/consensus.md) for the full consensus design.

src/xrpld/app/consensus/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/xrpld/app/ledger/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — ledger
+
+See the repo-level [AGENTS.md](../../../../AGENTS.md) for general guidance and [README.md](./README.md) for ledger lifecycle and fetch-pack design.

src/xrpld/app/ledger/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/xrpld/overlay/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — overlay
+
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general guidance and [README.md](./README.md) for the peer-protocol handshake, clustering, gossip, and monitoring design.

src/xrpld/overlay/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/xrpld/peerfinder/AGENTS.md

@@ -0,0 +1,3 @@
+# AGENTS.md — peerfinder
+
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general guidance and [README.md](./README.md) for the peer-discovery design.

src/xrpld/peerfinder/CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

src/xrpld/rpc/AGENTS.md

@@ -1,5 +1,5 @@
 # AGENTS.md — rpc
 
-See the repo-level [AGENTS.md](../../../AGENTS.md) for general build/test/style guidance, including the [API Changelog](../../../AGENTS.md#api-changelog) rule.
+See the repo-level [AGENTS.md](../../../AGENTS.md) for general build/test/style guidance, including the [API Changelog](../../../AGENTS.md#api-changelog) rule, and [README.md](./README.md) for the RPC subsystem design.
 
 A change to a public RPC method's behavior (new/changed/removed fields, parameters, or error conditions) is exactly the kind of API-visible change that rule covers — use `### Additions`, `### Deprecations`, etc. under `## Unreleased` as appropriate.