feat(agents): go-reviewer reads only Go hunks and names the rest

CHANGELOG.md

@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ## [Unreleased]
 
+### Changed
+- Agents: `go-reviewer` reviews only `.go` files and `go.mod`; it names the other files in a diff, unread, in its closing not-covered line.
+
 ## [0.6.2] - 2026-10-06
 
 ### Changed

agents/go-reviewer.md

@@ -50,6 +50,9 @@ the judgment a linter cannot — the bugs and smells that survive `gofmt`, `go v
   something, name the linter instead of belaboring it.
 - **Stay in scope.** Review the diff or files you were given. Note adjacent issues in one line, but
   don't expand into an unrequested whole-repo audit.
+- **Go only.** Review `.go` files and `go.mod`. A diff that also holds other files (fixtures, data,
+  scripts, docs) gets only its Go hunks read (`grep -n '^diff --git' <patch>` lists its files without
+  reading them); name the rest, unread, in the closing line of what you did not cover.
 
 ## How to review