Add analyzer framework for diagnostics #400
Description
Background:
- Pipeline should support analyzer-style passes (Roslyn/Ionide style) that emit diagnostics.
Scope:
- Define analyzer interfaces and integration points in pipeline execution.
- Allow analyzers over source/config/IR/artifacts without mutating outputs.
Acceptance criteria:
- Analyzers can emit diagnostics and attach to pipeline results.
- Analyzer ordering and grouping are supported.