Function dump_edge_histogram

tests/test_lang_contract.c:888–903

                                       NULL};

static void dump_edge_histogram(cbm_store_t *store, const char *project) {
    if (!store) {
        fprintf(stderr, "      └─ (no graph DB)\n");
        return;
    }
    char line[640] = {0};
    for (int i = 0; ALL_EDGE_TYPES[i]; i++) {
        int c = cbm_store_count_edges_by_type(store, project, ALL_EDGE_TYPES[i]);
        if (c > 0 && strlen(line) < sizeof(line) - 48) {
            char one[64];
            snprintf(one, sizeof(one), "%s=%d ", ALL_EDGE_TYPES[i], c);
            strncat(line, one, sizeof(line) - strlen(line) - 1);
        }
    }
    fprintf(stderr, "      └─ edges produced: [%s]\n", line[0] ? line : "(none)");
}

/* Index `files`, assert the named edge type appears at least `floor` times.
 * On failure, dump the full edge histogram so a regression is diagnosable. */