fix(driver-cli-common): resolve Medium code-review finding (Driver.Cli.Common-002)

FormatStatus now matches named codes against code & 0xFFFF0000 (high-word
mask) rather than exact equality, so status codes carrying sub-code or flag
bits in the low 16 bits (e.g. 0x80050001) still resolve to their named class.
For codes not in the named shortlist a severity-class fallback using the top
2 bits always emits Good / Uncertain / Bad rather than bare hex.

Updated the stale FormatStatus_unknown_codes_fall_back_to_hex_only test (its
expectation became invalid once the severity-class fallback was added) and
added new Theory cases exercising both the high-word matching and the
severity-class fallback paths.

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

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

@@ -81,7 +81,7 @@ a regression `[Theory]` asserting the pre-fix wrong names no longer apply.
 | Severity | Medium |
 | Category | Correctness & logic bugs |
 | Location | `src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Cli.Common/SnapshotFormatter.cs:101-122` |
-| Status | Open |
+| Status | Resolved |
 
 **Description:** `FormatStatus` matches the full 32-bit status word for exact equality
 against the shortlist. OPC UA status codes carry sub-code/flag bits in the low 16 bits
@@ -96,7 +96,7 @@ codes, or (b) match on the severity bits (`code & 0xC0000000`) to at least alway
 `Good` / `Uncertain` / `Bad` even when sub-code bits are set, and match the named codes
 on the masked code (`code & 0xFFFF0000`).
 
-**Resolution:** _(open)_
+**Resolution:** Resolved 2026-05-22 — `FormatStatus` now matches named codes on `code & 0xFFFF0000` and falls back to a severity-class label (`Good`/`Uncertain`/`Bad`) via `code & 0xC0000000` for unknown sub-codes; the stale "bare-hex for unknown codes" test expectation was corrected to reflect the new severity-class fallback.
 
 ### Driver.Cli.Common-003