Fix LogLevel: CLI phase suppression and case-insensitive "Default" config key

[Copilot]

Why make this change?

Two LogLevel bugs: dab start --LogLevel None still emits CLI-phase messages (version, config path, etc.), and using "Default" (capital D) as a key in telemetry.log-level config crashes startup with NotSupportedException.

What is this change?

CLI logger respects --LogLevel

• CustomConsoleLogger had a hardcoded _minimumLogLevel = LogLevel.Information, making it ignore the --LogLevel flag entirely.
• Added LogLevel parameter to CustomLoggerProvider / CustomConsoleLogger.
• Added Program.PreParseLogLevel() — scans raw args[] for --LogLevel before CommandLine.Parser runs — so the logger factory is configured at the right level before any CLI-phase output is emitted.
• Updated Utils.GetLoggerFactoryForCli(LogLevel) to wire this through.

Case-insensitive "Default" key in config

• IsLoggerFilterValid used string.Equals (ordinal), so "Default" failed against the registered "default" filter.
• GetConfiguredLogLevel used TryGetValue("default") (case-sensitive), silently ignoring "Default" keys.
• Both fixed with StringComparison.OrdinalIgnoreCase / LINQ FirstOrDefault.

// Now works — previously threw NotSupportedException
"telemetry": {
  "log-level": {
    "Default": "warning"
  }
}

# Now silent — previously emitted "Information: Microsoft.DataApiBuilder ..."
dab start --LogLevel None

How was this tested?

• Integration Tests
• Unit Tests
  • TestPreParseLogLevel (10 cases): validates pre-parse logic for all levels, numeric forms, =-syntax, and case variants.
  • TestEngineStartUpWithVerboseAndLogLevelOptions: narrowed to Trace/Debug/Information (levels that still produce CLI output).
  • TestEngineStartUpWithHighLogLevelOptions (new): Warning/Error/Critical/None — asserts process starts without checking stdout.
  • ValidStringLogLevelFilters: added "Default" (capital D) data row to cover the case-insensitive validation fix.

Sample Request(s)

# Suppress all output
dab start --LogLevel None

# Config key now case-insensitive
# dab-config.json:
# "telemetry": { "log-level": { "Default": "none" } }
dab start

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: LogLevel incorrect behavior and failing</issue_title>
<issue_description>## What?

LogLevel isn't working as expected.

Example

This is the normal DAB start output

C:\Temp\dab-todo-test>dab start
Information: Microsoft.DataApiBuilder 1.7.90
Information: Config not provided. Trying to get default config based on DAB_ENVIRONMENT...
Information: Environment variable DAB_ENVIRONMENT is (null)
Loading config file from C:\Temp\dab-todo-test\dab-config.json.
Information: Loaded config file: dab-config.json
Information: Setting default minimum LogLevel: Debug for Development mode.
Starting the runtime engine...
Loading config file from C:\Temp\dab-todo-test\dab-config.json.
Monitoring config: dab-config.json for hot-reloading.
info: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[63]
      User profile is available. Using 'C:\Users\jnixon\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
info: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      [Todos] REST path: /api/Todos
dbug: Azure.DataApiBuilder.Core.Resolvers.IQueryExecutor[0]
       Executing query: SELECT STE.type_desc FROM sys.triggers ST inner join sys.trigger_events STE On ST.object_id = STE.object_id AND ST.parent_id = object_id(@param0 + '.' + @param1) WHERE ST.is_disabled = 0;
dbug: Azure.DataApiBuilder.Core.Resolvers.IQueryExecutor[0]
       Executing query: SELECT ifsc.COLUMN_NAME from sys.columns as sc INNER JOIN INFORMATION_SCHEMA.COLUMNS as ifsc ON (sc.is_computed = 1 or ifsc.DATA_TYPE = 'timestamp') AND sc.object_id = object_id(@param0+'.'+@param1) AND ifsc.TABLE_SCHEMA = @param0 AND ifsc.TABLE_NAME = @param1 AND ifsc.COLUMN_NAME = sc.name;
dbug: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      Logging primary key information for entity: Todos.
dbug: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      Primary key column name: Id
      Primary key mapped name: Id
      Type: Int32
      IsNullable: False
      IsAutoGenerated: True
info: Azure.DataApiBuilder.Service.Startup[0]
      Successfully completed runtime initialization.
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://localhost:5000
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Production
info: Microsoft.Hosting.Lifetime[0]
      Content root path: C:\Temp\dab-todo-test

Suppress ASPNET logging

set Logging__LogLevel__Default=None

This works.

C:\Temp\dab-todo-test>set Logging__LogLevel__Default=None

C:\Temp\dab-todo-test>dab start
Information: Microsoft.DataApiBuilder 1.7.90
Information: Config not provided. Trying to get default config based on DAB_ENVIRONMENT...
Information: Environment variable DAB_ENVIRONMENT is (null)
Loading config file from C:\Temp\dab-todo-test\dab-config.json.
Information: Loaded config file: dab-config.json
Information: Setting default minimum LogLevel: Debug for Development mode.
Starting the runtime engine...
Loading config file from C:\Temp\dab-todo-test\dab-config.json.
Monitoring config: dab-config.json for hot-reloading.
info: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      [Todos] REST path: /api/Todos
dbug: Azure.DataApiBuilder.Core.Resolvers.IQueryExecutor[0]
       Executing query: SELECT STE.type_desc FROM sys.triggers ST inner join sys.trigger_events STE On ST.object_id = STE.object_id AND ST.parent_id = object_id(@param0 + '.' + @param1) WHERE ST.is_disabled = 0;
dbug: Azure.DataApiBuilder.Core.Resolvers.IQueryExecutor[0]
       Executing query: SELECT ifsc.COLUMN_NAME from sys.columns as sc INNER JOIN INFORMATION_SCHEMA.COLUMNS as ifsc ON (sc.is_computed = 1 or ifsc.DATA_TYPE = 'timestamp') AND sc.object_id = object_id(@param0+'.'+@param1) AND ifsc.TABLE_SCHEMA = @param0 AND ifsc.TABLE_NAME = @param1 AND ifsc.COLUMN_NAME = sc.name;
dbug: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      Logging primary key information for entity: Todos.
dbug: Azure.DataApiBuilder.Core.Services.ISqlMetadataProvider[0]
      Primary key column name: Id
      Primary key mapped name: Id
      Type: Int32
      IsNullable: False
      IsAutoGenerated: True
info: Azure.DataApiBuilder.Service.Startup[0]
      Successfully completed runtime initialization.

Suppress DAB Logging at Command Line

dab start --LogLevel None

⭐⭐ This does not work as expected. None should result in ZERO logging. Not a char, except errors.

C:\Temp\dab-todo-test>dab start --LogLevel None
Information: Microsoft.DataApiBuilder 1.7.90
Information: Config not provided. Trying to get default config based on DAB_ENVIRONMENT...
Information: Environment variable DAB_ENVIRONMENT is (null)
Loading config file from C:\Temp\dab-todo-test\dab-config.json.
Information: Loaded config file: dab-config.json
In...

</details>



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- Fixes Azure/data-api-builder#3201

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