style(lint): drop duplicate rule code declaration

docs/DECISIONS.md

@@ -32,3 +32,33 @@ The resolver is invoked automatically when `img.Externals` is non-empty; it
 runs `go list` as a subprocess (consistent with `toolchainObjectPreamble`
 which already calls `go tool asm`).  All symbol data is cached per package
 for the lifetime of the GOOBJ emission.
+
+## 2026-08-29 tooling round
+
+- `lint abi0-register-args`: flags kernels whose `// func` parameters are
+  never read from the FP frame.  Motivated by a real latent bug: kernels
+  reading arguments from registers pass every test while the autogenerated
+  `F.abi0` wrapper happens to leave the caller's register values intact, and
+  break on a toolchain upgrade.
+- `lint nonportable-register-name`: the RAX/EAX register spellings are a gasm
+  extension; go tool asm rejects them, so files using them only link through
+  the gasm goobj path.
+- `lint unencodable-instruction`: a mnemonic in the architecture table that
+  `asm.Encodable` rejects is flagged at edit time instead of failing at
+  assembly time.
+- `audit-instructions`: black-box diff of the encoder against go tool asm.
+  As of this round the tables fully overlap on names; the audit exists to
+  catch drift in both directions (future supersets and future gaps).
+- `scaffold differential`: generates the direct-call differential skeleton
+  (two independent seed sets, output and in-place buffer comparison) that a
+  pipeline-level fuzz can never replace.
+- `verify --args`: scalar arguments for `-call`, closing the repro gap where
+  only buffers could be supplied.
+- `debug --script/--timeout/--cover`: headless debugging with a watchdog
+  armed before the ptrace attach (untracing sandboxes hang the attach), and
+  label-level block coverage for the "did my test ever enter that branch"
+  question.
+- Superset policy remains: gasm may accept spellings and encodings go tool
+  asm lacks, but such kernels ship only via `gasm asm --format goobj`; the
+  audit reports the superset surface.  The register-alias superset is warned
+  about by lint because the default `go build` path cannot consume it.

lint/registers.go

@@ -11,12 +11,10 @@ import (
 	"sourcedock.dev/petrbalvin/gasm-devkit/token"
 )
 
-// CodeNonportableRegister flags R/E-prefixed amd64 register spellings.
-const CodeNonportableRegister = "nonportable-register-name"
-
 // amd64WordNames are the canonical 64-bit register spellings of go tool asm:
 // the assembler has no RAX/EAX/RBX forms, and a file using them assembles
-// under gasm but fails under the toolchain it must ship with.
+// under gasm but fails under the toolchain it must ship with.  The rule code
+// (CodeNonportableRegister) is declared in lint.go.
 var amd64WordNames = map[string]string{
 	"AX": "AX", "BX": "BX", "CX": "CX", "DX": "DX",
 	"SI": "SI", "DI": "DI", "BP": "BP", "SP": "SP",