fix(clickhouse): harden R/W path P0–P3 (cleanup, durability, rollups)

Honest TTL cleanup semantics; enqueue-safe dedup with flush retry and writer
metrics; model insert hooks; latest-per-node and hourly metric/openresty
rollups; small-host pool/async defaults, traffic hourly TTL, and UV labeling.

internal/repository/analytics/access_log_test.go

@@ -99,6 +99,9 @@ type mockConn struct {
 	batchQuery    string
 	prepareCalled bool
 	preparedQuery string
+	queries       []string
+	queryArgs     [][]any
+	queryFn       func(ctx context.Context, query string, args ...any) (driver.Rows, error)
 }
 
 func (m *mockConn) Contributors() []string { return nil }
@@ -107,8 +110,13 @@ func (m *mockConn) ServerVersion() (*driver.ServerVersion, error) { return nil,
 
 func (m *mockConn) Select(_ context.Context, _ any, _ string, _ ...any) error { return nil }
 
-func (m *mockConn) Query(_ context.Context, _ string, _ ...any) (driver.Rows, error) {
-	return nil, nil
+func (m *mockConn) Query(ctx context.Context, query string, args ...any) (driver.Rows, error) {
+	m.queries = append(m.queries, query)
+	m.queryArgs = append(m.queryArgs, args)
+	if m.queryFn != nil {
+		return m.queryFn(ctx, query, args...)
+	}
+	return &mockRows{}, nil
 }
 
 func (m *mockConn) QueryRow(_ context.Context, _ string, _ ...any) driver.Row { return nil }
@@ -158,4 +166,96 @@ func (m *mockBatch) Rows() int { return len(m.rows) }
 
 func (m *mockBatch) Columns() []column.Interface { return nil }
 
-func (m *mockBatch) Close() error { return nil }
+func (m *mockBatch) Close() error { return nil }
+
+// mockRows is an empty driver.Rows implementation for query-path unit tests.
+type mockRows struct {
+	index int
+	data  [][]any
+	err   error
+}
+
+func (m *mockRows) Next() bool {
+	if m.err != nil {
+		return false
+	}
+	if m.index >= len(m.data) {
+		return false
+	}
+	m.index++
+	return true
+}
+
+func (m *mockRows) Scan(dest ...any) error {
+	if m.err != nil {
+		return m.err
+	}
+	if m.index == 0 || m.index > len(m.data) {
+		return nil
+	}
+	row := m.data[m.index-1]
+	for i := range dest {
+		if i >= len(row) {
+			break
+		}
+		if err := assignMockScanValue(dest[i], row[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m *mockRows) ScanStruct(_ any) error { return nil }
+
+func (m *mockRows) ColumnTypes() []driver.ColumnType { return nil }
+
+func (m *mockRows) Totals(_ ...any) error { return nil }
+
+func (m *mockRows) Columns() []string { return nil }
+
+func (m *mockRows) Close() error { return nil }
+
+func (m *mockRows) Err() error { return m.err }
+
+func (m *mockRows) HasData() bool { return len(m.data) > 0 }
+
+func assignMockScanValue(dest any, value any) error {
+	switch d := dest.(type) {
+	case *string:
+		if v, ok := value.(string); ok {
+			*d = v
+		}
+	case *uint64:
+		switch v := value.(type) {
+		case uint64:
+			*d = v
+		case int:
+			*d = uint64(v)
+		case int64:
+			*d = uint64(v)
+		}
+	case *int64:
+		switch v := value.(type) {
+		case int64:
+			*d = v
+		case int:
+			*d = int64(v)
+		case uint64:
+			*d = int64(v)
+		}
+	case *float64:
+		switch v := value.(type) {
+		case float64:
+			*d = v
+		case float32:
+			*d = float64(v)
+		case int:
+			*d = float64(v)
+		}
+	case *time.Time:
+		if v, ok := value.(time.Time); ok {
+			*d = v
+		}
+	}
+	return nil
+}