feat: replace noisy failure for missing bosch sensor on lab multi bus

Author: CameronBrooks11

examples/core_usage/linux/mixed_bus_lab_validation/README.md

@@ -16,6 +16,7 @@ Single pass, then exits:
 2. Sends a default `SET_REPLY` query to each expected CRUMBS device and prints reply data.
 3. Sends `R` command to EZO pH and DO sensors, waits, reads response frame, prints status + text payload.
 4. Optionally probes Bosch candidates (`0x76`, `0x77`) for chip ID register (`0xD0`) and prints one raw sample read (`0xF7`, 6 bytes) when present.
+   Missing optional Bosch addresses are reported as `not present`.
 
 Exit code is non-zero on validation failure.
 

examples/core_usage/linux/mixed_bus_lab_validation/main.c

@@ -206,17 +206,24 @@ static bool test_bosch_candidate(crumbs_context_t *ctx,
     dev.delay_fn = crumbs_linux_delay_us;
     dev.io = (void *)bus;
 
+#if defined(__linux__)
+    /* Optional probe: suppress expected low-level I/O errors for missing addrs. */
+    lw_set_error_logging(&bus->bus, 0);
+#endif
     rc_chip = crumbs_i2c_dev_read_reg_u8(&dev,
                                          0xD0u,
                                          &chip_id,
                                          1u,
                                          BUS_TIMEOUT_US,
                                          1,
                                          crumbs_linux_write_then_read);
+#if defined(__linux__)
+    lw_set_error_logging(&bus->bus, 1);
+#endif
 
     if (rc_chip != CRUMBS_I2C_DEV_OK)
     {
-        printf("Bosch addr=0x%02X chip_id read failed rc=%d\n", addr, rc_chip);
+        printf("Bosch addr=0x%02X not present (chip_id rc=%d)\n", addr, rc_chip);
         return false;
     }