fix: address PR review critical and high findings

- Remove duplicate _cap_log_content definition (dead code merge artifact)
  from manager.py; keep byte-count version that correctly handles multibyte UTF-8
- Fix storage.py unassigned handler reading wrong key (unassignedDevices → disks)
  — query already fetched `disks {}` but handler returned empty list every call
- Add null checks to all 8 Docker organizer object mutations; raise ToolError
  instead of silently returning success=True with organizer=None
- Raise ToolError in docker logs when server returns no log data
- Extract notification object from create response (was returning raw GraphQL
  wrapper dict instead of the notification itself)
- Raise ToolError in test_subscription_query on connection failure and unexpected
  exceptions (was returning error dicts, bypassing error handling)
- Remove stale "Bug N fix" inline comments from diagnostics.py
- Update docker.py module docstring to reflect 26 actions (was 15)
- Bump version 0.4.1 → 0.4.2

Co-authored-by: Claude <claude@anthropic.com>

pyproject.toml

@@ -10,7 +10,7 @@ build-backend = "hatchling.build"
 # ============================================================================
 [project]
 name = "unraid-mcp"
-version = "0.4.1"
+version = "0.4.2"
 description = "MCP Server for Unraid API - provides tools to interact with an Unraid server's GraphQL API"
 readme = "README.md"
 license = {file = "LICENSE"}