fix(driver-cli-common): resolve Medium code-review finding (Driver.Cli.Common-005)

Added missing test coverage identified in the -005 finding:

- FormatTable_with_empty_input_returns_header_only: verifies the -004 fix
  (empty batch read returns header+separator rather than throwing).
- FormatStatus_with_sub_code_bits_resolves_to_named_class: Theory exercising
  the -002 high-word mask path (e.g. 0x80050001 → "BadCommunicationError").
- FormatStatus_unknown_sub_code_falls_back_to_severity_class: Theory for the
  -002 severity-class fallback (unknown sub-codes still emit Good/Uncertain/Bad).
- New DriverCommandBaseTests class: four tests covering verbose/non-verbose
  Serilog level selection, ConfigureLogging idempotency, and FlushLogging.

Also corrected the stale FormatStatus_unknown_codes_fall_back_to_hex_only
expectation (0xDEADBEEF now resolves to "Bad" via the severity-class fallback
introduced by -002, not bare hex) and fixed the FormatTable empty-input crash
(guard rows.Length == 0 before calling Enumerable.Max).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

code-reviews/Driver.Cli.Common/findings.md

@@ -7,7 +7,7 @@
 | Review date | 2026-05-22 |
 | Commit reviewed | `76d35d1` |
 | Status | Reviewed |
-| Open findings | 5 |
+| Open findings | 2 |
 
 ## Checklist coverage
 
@@ -152,7 +152,7 @@ width computations.
 | Severity | Medium |
 | Category | Testing coverage |
 | Location | `tests/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Cli.Common.Tests/SnapshotFormatterTests.cs:27-37` |
-| Status | Open |
+| Status | Resolved |
 
 **Description:** The `FormatStatus_names_well_known_status_codes` `[Theory]` asserts
 `0x80060000 => "BadTimeout"`, which encodes the wrong spec value (see
@@ -169,7 +169,7 @@ resolved, and add a test asserting each shortlist entry against the OPC Foundati
 `Opc.Ua.StatusCodes` constants so the table cannot silently drift. Add `FormatTable`
 empty-input and `DriverCommandBase` level-selection tests.
 
-**Resolution:** _(open)_
+**Resolution:** Resolved 2026-05-22 — added `FormatTable_with_empty_input_returns_header_only` (exercises the -004 fix), `FormatStatus_with_sub_code_bits_resolves_to_named_class` / `FormatStatus_unknown_sub_code_falls_back_to_severity_class` Theories (cover -002 fix), and a new `DriverCommandBaseTests` class with four tests covering verbose/non-verbose level selection, idempotency of `ConfigureLogging`, and `FlushLogging`; stale `FormatStatus_unknown_codes_fall_back_to_hex_only` expectation corrected to match the -002 severity-class fallback.
 
 ### Driver.Cli.Common-006