chore(config): migrate OttlTransformConfiguration to typed config (#1997)

Cut the OTTL transform processor over from the raw
`GenericConfiguration` map to the typed
`SalukiConfiguration` model, following the pattern already applied to
the sibling OTTL filter
processor.

- `OttlTransformConfiguration::from_configuration` now takes the
resolved
`domains::traces::OttlTransform` settings and copies them directly,
instead of deserializing an
`OttlTransformConfig` out of `GenericConfiguration`. The component-local
config module (its
`ErrorMode` enum and `OttlTransformConfig` struct) is removed; the
component reuses the model's
  shared `OttlErrorMode`.
- The call site in `run.rs` reads
`saluki.domains.traces.ottl_transform`. Since this was the last
consumer of the raw config in
`add_baseline_traces_pipeline_to_blueprint`, the now-unused
  `GenericConfiguration` parameter is dropped from that function.
- The seed source `OttlTransformConfig` in `saluki_only.rs` is aligned
with the filter's: its
`error_mode` deserializes directly into `OttlErrorMode` (rather than a
loose `Option<String>` fed
through a hand-rolled parse helper) and it now rejects unknown fields,
restoring the strict
  deserialization the original component had.

`ottl_transform_config` is absent from the vendored Datadog schema, so
it is a Saluki-only key on
the seed track; there is no witnessed alias for it.

- [x] Non-functional (chore, refactoring, docs)

- Rewrote the component tests to build from typed traces settings; all
OTTL transform tests pass.
- Added an `ottl_transform_config` round-trip rejection test mirroring
the filter's.
- `make build-schema-overlay` leaves the tree unchanged; `make fmt`,
`make check-all`, `make test`,
  and `make check-docs` all pass.

- Progresses #1788
- Merges into #1987

Author: webern

bin/agent-data-plane/src/cli/run.rs

@@ -442,7 +442,7 @@ async fn create_topology(
     }
 
     if dp_config.traces_pipeline_required() {
-        add_baseline_traces_pipeline_to_blueprint(&mut blueprint, config, config_system, env_provider).await?;
+        add_baseline_traces_pipeline_to_blueprint(&mut blueprint, config_system, env_provider).await?;
     }
 
     // Now we move on to our actual data pipelines.
@@ -668,8 +668,7 @@ async fn add_baseline_service_checks_pipeline_to_blueprint(
 }
 
 async fn add_baseline_traces_pipeline_to_blueprint(
-    blueprint: &mut TopologyBlueprint, config: &GenericConfiguration, config_system: &ConfigurationSystem,
-    env_provider: &ADPEnvironmentProvider,
+    blueprint: &mut TopologyBlueprint, config_system: &ConfigurationSystem, env_provider: &ADPEnvironmentProvider,
 ) -> Result<(), GenericError> {
     let saluki = config_system.config();
     let dd_traces_config = DatadogTraceConfiguration::from_configuration(
@@ -685,7 +684,7 @@ async fn add_baseline_traces_pipeline_to_blueprint(
         .error_context("Failed to configure Trace Sampler transform.")?;
     let ottl_filter_config = OttlFilterConfiguration::from_configuration(&saluki.domains.traces.ottl_filter)
         .error_context("Failed to configure OTTL filter processor.")?;
-    let ottl_transform_config = OttlTransformConfiguration::from_configuration(config)
+    let ottl_transform_config = OttlTransformConfiguration::from_configuration(&saluki.domains.traces.ottl_transform)
         .error_context("Failed to configure OTTL transform processor.")?;
     let dd_traces_enrich_config = ChainedConfiguration::default()
         .with_transform_builder("ottl_filter", ottl_filter_config)