chore: baseline snapshot before moderation-strictness feature

Repo .git was damaged (refs/ missing, index truncated, object store near-empty).
Repaired via git init (rebuilt refs), stale index preserved as .git/index.corrupt-20260910.bak,
then full worktree committed as a rollback baseline.

internal/shared/blockword_test.go

@@ -0,0 +1,32 @@
+package shared
+
+import "testing"
+
+func TestBlockWordHit(t *testing.T) {
+	cases := []struct {
+		name  string
+		words string // CSV 词表
+		text  string
+		word  string
+		hit   bool
+	}{
+		{name: "empty list", words: "", text: "广告", word: "", hit: false},
+		{name: "empty text", words: "广告", text: "", word: "", hit: false},
+		{name: "single hit", words: "广告,spam", text: "请勿发广告", word: "广告", hit: true},
+		{name: "second word hit", words: "广告,spam", text: "buy now spam!", word: "spam", hit: true},
+		{name: "no hit", words: "广告,spam", text: "你好呀", word: "", hit: false},
+		{name: "dirty csv trims space", words: " 广告 , spam ", text: "这是广告", word: "广告", hit: true},
+		{name: "dirty csv empty items skipped", words: "广告,,,spam", text: "spam again", word: "spam", hit: true},
+		{name: "substring semantics", words: "抽奖", text: "参与抽奖活动", word: "抽奖", hit: true},
+		{name: "chinese word bytes safe", words: "屏蔽", text: "你被屏蔽了吗", word: "屏蔽", hit: true},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			gotWord, gotHit := BlockWordHit(c.words, c.text)
+			if gotHit != c.hit || gotWord != c.word {
+				t.Fatalf("BlockWordHit(%q, %q) = (%q, %v), want (%q, %v)",
+					c.words, c.text, gotWord, gotHit, c.word, c.hit)
+			}
+		})
+	}
+}