fix: add test to structure.json, document ./test_all.sh

- Add goodErrgroupWithContextForLoop to structure.json
- Update CLAUDE.md to emphasize using ./test_all.sh before committing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mpyw

CLAUDE.md

@@ -176,25 +176,24 @@ The gotask checker handles `github.com/siketyan/gotask` library:
 ## Development Commands
 
 ```bash
-# Run all tests
-go test ./...
-
-# Run tests with verbose output
-go test -v ./...
+# Run ALL tests (ALWAYS use this before committing)
+./test_all.sh
 
 # Run golangci-lint
 golangci-lint run ./...
 
 # Format code
 go fmt ./...
-
-# Validate test metadata (structure.json)
-cd testdata/metatest && go test -v ./...
-
-# Validate JSON schema
-cd testdata/metatest && go run github.com/santhosh-tekuri/jsonschema/cmd/jv@29cbed9 structure.schema.json structure.json
 ```
 
+> [!IMPORTANT]
+> Always use `./test_all.sh` before committing. This script runs:
+> 1. JSON schema validation for `structure.json`
+> 2. Test metadata validation (ensures all test functions are in `structure.json`)
+> 3. All analyzer tests
+>
+> Running only `go test ./...` will miss structure validation failures.
+
 ## Adding a New Checker
 
 1. Create `internal/checkers/<name>/checker.go`:

test_all.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -x
+
+go run github.com/santhosh-tekuri/jsonschema/cmd/jv@29cbed9 testdata/metatest/structure.schema.json testdata/metatest/structure.json
+go test ./testdata/metatest/validation_test.go
+go test -v ./...

testdata/metatest/structure.json

@@ -2148,6 +2148,22 @@
       },
       "level": "basic"
     },
+    "derivedCtxInForLoopWithFunctionVariable": {
+      "title": "Derived ctx in for loop with function variable",
+      "targets": [
+        "errgroup"
+      ],
+      "variants": {
+        "good": {
+          "description": "Real-world production pattern: derived ctx used in closure inside for loop",
+          "functions": {
+            "errgroup": "goodErrgroupWithContextForLoop"
+          }
+        },
+        "bad": null
+      },
+      "level": "basic"
+    },
     "literalWithDerivedCtxWithDefer": {
       "title": "Literal with derived ctx - with defer",
       "targets": [