…any string key (#7689)

## Context

Part of **Configuration Inversion (Step 4)** - Stack progress:
1. [#7548](#7548) - Add
GitLab step and JSON configuration file
2. [#7688](#7688) -
Cleanup configuration / platform keys + analyzers
3. [#7698](#7698) -
Source generator for ConfigurationKeys
4. **→ [#7689](#7689) -
Aliases handling and analyzers (this PR)**
5. [#7931](#7931) -
Replace manual ConfigurationKeys with generated version
6. #[7932](#7932 Forbid
use of System.Environment methods and adapt everywhere

## Summary

Adds source generator for configuration key aliases, integrates alias
resolution into `ConfigurationBuilder`, and adds Roslyn analyzers to
enforce proper configuration key usage.

## Changes

**Alias Source Generator:**
- `ConfigKeyAliasesSwitcherGenerator` reads aliases from
`supported-configurations.json`
- Auto-generates switch statements to resolve primary keys from aliases
- Generated for all target frameworks (net461, netstandard2.0,
netcoreapp3.1, net6.0)

**ConfigurationBuilder Improvements:**
- Integrated alias resolution directly into
`ConfigurationBuilder.WithKeys()`
- Removed manual fallback overloads throughout codebase
- Added `GetKeyWithAlias()` method to `IConfigurationSource` interface

**IntegrationSettings Special Handling:**
- Updated to use pattern-based key construction (e.g.,
`DD_TRACE_{INTEGRATION}_ENABLED`)
- Simplified configuration reading by leveraging alias system

**Roslyn Analyzers:**
- **DD0007**: `PlatformKeysAnalyzer` - Enforces use of `PlatformKeys`
for external platform environment variables
- **DD0008**: `ConfigurationBuilderWithKeysAnalyzer` - Enforces use of
[ConfigurationKeys](cci:2://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/ConfigurationKeys.Logging.cs:9:0-58:1)/`PlatformKeys`
constants in `ConfigurationBuilder.WithKeys()` calls

**Special Cases:**
- Fixed `DatadogLoggingFactory` to handle deprecated `DD_TRACE_LOG_PATH`
with proper analyzer suppression
- Updated configuration tests to work with alias resolution

## Motivation

Completes configuration inversion by:
- Auto-generating alias resolution from `supported-configurations.json`
- Eliminating manual fallback chains
- Enforcing compile-time validation of configuration keys
- Preventing hardcoded strings and typos

## Test Coverage

- Added `ConfigKeyAliasesSwitcherGeneratorTests` with comprehensive test
coverage
- Added `PlatformKeysAnalyzerTests` with 146 lines of tests
- Added `ConfigurationBuilderWithKeysAnalyzerTests` with 538 lines of
tests
- Updated existing configuration tests for alias support
- All tests pass with new alias system

## Related Work

Builds on #7548 (configuration registry), #7688 (PlatformKeys
separation), and #7698 (source generator for ConfigurationKeys).

…nes in the whole solution (#7931)

(This PR is actually
#7697 that accidentally
got closed)

## Context

Part of **Configuration Inversion (Step 5)** - Stack progress:
1. [#7548](#7548) - Add
GitLab step and JSON configuration file
2. [#7688](#7688) -
Cleanup configuration / platform keys + source generator
3. [#7698](#7698) -
Aliases handling via source generator
4. [#7689](#7689) -
Analyzers for platform and ConfigurationBuilder
5. **→ [#7931](#7697) -
Replace manual ConfigurationKeys by generated ones in the whole solution
(this PR)**
6. [#7932](#7932) -
Forbid use of System.Environment methods and adapt everywhere
7. [#7937](#7937) -
Integration names to generated keys

## Summary of changes

Fixed the
[ConfigurationKeysGenerator](cci:2://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/Configuration/ConfigurationKeysGenerator.cs:21:0-958:1)
to properly read and apply the
[configuration_keys_mapping.json](cci:7://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/configuration_keys_mapping.json:0:0-0:0)
file, and extracted common file header comments to a reusable constant.

**Key changes:**
- Fixed JSON array extraction in
[ParseMappingFile](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/Configuration/ConfigurationKeysGenerator.cs:350:4-524:5)
method - the generator was incorrectly trying to extract the
`"mappings"` field as an object instead of an array
- Extracted configuration generator comments to
`Constants.ConfigurationGeneratorComment` for reuse across multiple
generators
- Updated both
[ConfigurationKeysGenerator](cci:2://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/Configuration/ConfigurationKeysGenerator.cs:21:0-958:1)
and
[ConfigKeyAliasesSwitcherGenerator](cci:2://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/Configuration/ConfigKeyAliasesSwitcherGenerator.cs:24:0-340:1)
to use the shared constant
- Added documentation as to how to add a key now

## Reason for change

The
[configuration_keys_mapping.json](cci:7://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/configuration_keys_mapping.json:0:0-0:0)
file was being ignored during code generation, causing the generator to
produce incorrect constant names. This meant that any manual edits to
constant names in the mapping file were not being respected, and the
generated code would use auto-generated names instead of the explicitly
mapped ones.

Additionally, the file header comments explaining that files are
auto-generated were duplicated across generators, violating DRY
principles.

## Implementation details

1. **Fixed array extraction logic**: Replaced the call to
[JsonReader.ExtractJsonObjectSection()](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/Configuration/JsonReader.cs:16:4-91:5)
with custom array extraction code that:
   - Finds the `"mappings":` key in the JSON
   - Locates the opening `[` bracket
   - Tracks bracket nesting to find the matching closing `]`
   - Extracts the complete array content

2. **Resolved variable scope issue**: Reused existing `inString` and
`escapeNext` variables from the outer scope instead of redeclaring them,
fixing compilation errors.

3. **Centralized header comments**: Created
`Constants.ConfigurationGeneratorComment` containing the standardized
auto-generation notice and updated both generators to use it.

## Test coverage

- Verified the generator builds successfully without errors
- The mapping file is now properly parsed and applied during code
generation
- Generated constant names now match the mappings defined in
[configuration_keys_mapping.json](cci:7://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/configuration_keys_mapping.json:0:0-0:0)

## Other details

This fix ensures that the explicit naming conventions defined in
[configuration_keys_mapping.json](cci:7://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/configuration_keys_mapping.json:0:0-0:0)
are respected, maintaining consistency with the existing codebase and
preventing future confusion when constant names don't match their
expected values.

---------

Co-authored-by: Andrew Lock <andrew.lock@datadoghq.com>

## Summary of changes

In [this PR](#7932),
benchmark tests were broken because of a compilation error. We did not
detect that until merged into master since the task run-benchmarks is
not required for merging into master.

` [ERR] RunBenchmarks:
C:\dd-trace-dotnet\tracer\test\benchmarks\Benchmarks.Trace\Asm\AppSecBenchmarkUtils.cs(79,47):
error CS7036: There is no argument given that corresponds to the
required parameter 'ddDotnetTracerHome' of
'WafLibraryInvoker.Initialize(string, string, string)'
[C:\dd-trace-dotnet\tracer\test\benchmarks\Benchmarks.Trace\Benchmarks.Trace.csproj::TargetFramework=net472]
    `
## Reason for change

## Implementation details

## Test coverage

## Other details
<!-- Fixes #{issue} -->


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## Context

Part of **Configuration Inversion (Step 6)** - Stack progress:
1. [#7548](#7548) - Add
GitLab step and JSON configuration file
2. [#7688](#7688) -
Cleanup configuration / platform keys + source generator
3. [#7698](#7698) -
Aliases handling via source generator
4. [#7689](#7689) -
Analyzers for platform and ConfigurationBuilder
5. [#7931](#7931) -
Replace manual ConfigurationKeys by generated ones in the whole solution
6. [#7932](#7932) -
Forbid use of System.Environment methods and adapt everywhere
7. **→ [#7937](#7937) -
Integration names to generated keys (this PR)**
## Summary of changes

Extends the `EnumExtensionsGenerator` to generate
[IntegrationNameToKeys](cci:2://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Generated/net6.0/Datadog.Trace.SourceGenerators/EnumExtensionsGenerator/IntegrationNameToKeys.g.cs:14:4-392:5)
class for the `IntegrationId` enum, providing centralized configuration
key mapping for integrations including enabled, analytics enabled, and
analytics sample rate keys. Also fixes AdoNet instrumentation
compilation error.

## Reason for change

- Eliminates code duplication in configuration key generation across the
codebase
- Provides compile-time safety for integration configuration key access
- Centralizes key pattern definitions with proper documentation
- Ensures consistency across all integration key formats (canonical,
mixed case, short aliases)

## Implementation details

- **Source Generator**: Extended `EnumExtensionsGenerator` with
[GenerateIntegrationNameToKeys](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace.SourceGenerators/EnumExtensions/Sources.cs:82:4-178:5)
method that generates:
- `AllIntegrationEnabledKeys` array containing all enabled configuration
keys
-
[GetIntegrationEnabledKeys(string)](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Generated/net6.0/Datadog.Trace.SourceGenerators/EnumExtensionsGenerator/IntegrationNameToKeys.g.cs:102:8-197:9)
- returns enabled keys for an integration
-
[GetIntegrationAnalyticsEnabledKeys(string)](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Generated/net6.0/Datadog.Trace.SourceGenerators/EnumExtensionsGenerator/IntegrationNameToKeys.g.cs:198:8-294:9)
- returns analytics enabled keys (marked obsolete)
-
[GetIntegrationAnalyticsSampleRateKeys(string)](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Generated/net6.0/Datadog.Trace.SourceGenerators/EnumExtensionsGenerator/IntegrationNameToKeys.g.cs:295:8-391:9)
- returns analytics sample rate keys (marked obsolete)
- Key pattern constants (`IntegrationEnabledKeyPattern`,
`AnalyticsEnabledKeyPattern`, `AnalyticsSampleRateKeyPattern`)
- **Configuration**: Updated
[ConfigurationBuilder.WithIntegrationAnalyticsKey](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/ConfigurationSources/Telemetry/ConfigurationBuilder.cs:32:4-42:5)
and
[WithIntegrationAnalyticsSampleRateKey](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/src/Datadog.Trace/Configuration/ConfigurationSources/Telemetry/ConfigurationBuilder.cs:44:4-54:5)
to use generated methods

## Test coverage

- Added
[CanGenerateIntegrationNameToKeysForIntegrationId](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/test/Datadog.Trace.SourceGenerators.Tests/EnumExtensionsGeneratorTests.cs:411:4-527:5)
- verifies complete generated output with all three methods
- Added
[DoesNotGenerateIntegrationNameToKeysForNonIntegrationIdEnum](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/test/Datadog.Trace.SourceGenerators.Tests/EnumExtensionsGeneratorTests.cs:529:4-552:5)
- ensures generation only for `IntegrationId` enum
- Added
[IntegrationNameToKeysGeneratesCorrectKeyFormats](cci:1://file:///Users/anna.yafi/go/src/github.com/DataDog/dd-trace-dotnet3/tracer/test/Datadog.Trace.SourceGenerators.Tests/EnumExtensionsGeneratorTests.cs:554:4-670:5)
- validates key formats for various integration names
- All tests verify obsolete attributes, key patterns, and switch
expression logic