fix(pipeline): repair invalid JSON escape sequences from LLM output before parsing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ingestion/internal/pipeline/parse_test.go

@@ -59,3 +59,29 @@ func TestParseRawPages_MissingTitle(t *testing.T) {
 	assert.Empty(t, warnings)
 	assert.Empty(t, pages[0].Title)
 }
+
+func TestParseRawPages_InvalidEscapeRepaired(t *testing.T) {
+	// LLM copied markdown escaped list numbers (\.) into JSON — invalid escape
+	raw := "[{\"title\":\"Foo\",\"type\":\"concept\",\"content\":\"Step 4\\. Do it.\"}]"
+	pages, warnings := ParseRawPages(raw)
+	require.Len(t, pages, 1)
+	assert.Equal(t, "Foo", pages[0].Title)
+	assert.Contains(t, pages[0].Content, `4\.`)
+	assert.NotEmpty(t, warnings) // repair warning
+}
+
+func TestRepairJSON_FixesInvalidEscapes(t *testing.T) {
+	cases := []struct {
+		in   string
+		want string
+	}{
+		{`{"a":"foo\.bar"}`, `{"a":"foo\\.bar"}`},
+		{`{"a":"\\n is fine"}`, `{"a":"\\n is fine"}`}, // valid \n untouched
+		{`{"a":"\d+ items"}`, `{"a":"\\d+ items"}`},
+		{`{"a":"already \\ escaped"}`, `{"a":"already \\ escaped"}`}, // valid \\ untouched
+	}
+	for _, tc := range cases {
+		got := repairJSON(tc.in)
+		assert.Equal(t, tc.want, got, "input: %s", tc.in)
+	}
+}