# Roslyn Analyzer for Canonicalization Enforcement (STELLA0100)

## Module
__Analyzers

## Status
IMPLEMENTED

## Description
Custom Roslyn static analyzer (diagnostic STELLA0100) that enforces canonicalization boundaries at compile time. Detects code paths that cross resolver boundaries without proper canonicalization, preventing non-deterministic serialization from leaking into deterministic evaluation pipelines. Includes ResolverBoundaryAttribute for marking boundary methods.

## Implementation Details
- **Canonicalization Boundary Analyzer**: `src/__Analyzers/StellaOps.Determinism.Analyzers/CanonicalizationBoundaryAnalyzer.cs` -- Roslyn `DiagnosticAnalyzer` registered for C# syntax; reports diagnostic `STELLA0100` when code crosses canonicalization boundaries without proper serialization guards. Analyzes method invocations and property accesses to detect non-deterministic serialization patterns at resolver boundaries.
- **Analyzer Tests**: `src/__Analyzers/StellaOps.Determinism.Analyzers.Tests/CanonicalizationBoundaryAnalyzerTests.cs` -- unit tests verifying the analyzer correctly reports STELLA0100 diagnostics for boundary violations and does not produce false positives for correctly guarded code.

## E2E Test Plan
- [ ] Add the `StellaOps.Determinism.Analyzers` package to a test project and verify the STELLA0100 diagnostic is reported when a method crosses a canonicalization boundary without a serialization guard
- [ ] Verify the analyzer produces no diagnostics for code that correctly uses canonical serializers (e.g., `LedgerCanonicalJsonSerializer`, `Rfc8785JsonCanonicalizer`)
- [ ] Verify the analyzer integrates with `dotnet build` and causes a build warning (or error if configured via `.editorconfig`) for violations
- [ ] Verify the analyzer does not report false positives on non-serialization code paths or methods not annotated with `ResolverBoundaryAttribute`
- [ ] Verify the analyzer works with partial classes and cross-file method calls within the same assembly