[codex] Add SQL LIKE escaping helper

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Add shared SQL LIKE literal escaping for crawler search queries.
 - Add a safe tokenized FTS5 query helper for arbitrary user search input.
 - Preserve unrelated tracked mirror edits across write synchronization rebases.
 - Retry atomic branch-and-tag snapshot pushes after rebasing and retargeting unpublished tags.

store/query.go

@@ -0,0 +1,16 @@
+package store
+
+import "strings"
+
+// EscapeLike escapes a literal value for a LIKE expression using backslash as
+// the SQL ESCAPE character. Callers must add `ESCAPE '\'` to the expression.
+func EscapeLike(value string) string {
+	var escaped strings.Builder
+	for _, r := range value {
+		if r == '\\' || r == '%' || r == '_' {
+			escaped.WriteRune('\\')
+		}
+		escaped.WriteRune(r)
+	}
+	return escaped.String()
+}

store/query_test.go

@@ -0,0 +1,16 @@
+package store
+
+import "testing"
+
+func TestEscapeLike(t *testing.T) {
+	tests := map[string]string{
+		"plain":       "plain",
+		`100%_ready`:  `100\%\_ready`,
+		`path\value%`: `path\\value\%`,
+	}
+	for input, want := range tests {
+		if got := EscapeLike(input); got != want {
+			t.Errorf("EscapeLike(%q) = %q, want %q", input, got, want)
+		}
+	}
+}