docs(rules): give each C# rule statement one authoritative file

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

shared/rules/csharp/references/safety-and-errors.md

@@ -7,8 +7,7 @@ Apply these rules when handling external input, failures, logs, or sensitive inf
 * Fail fast for invalid arguments or impossible state. Do not use exceptions for routine control flow or swallow unexpected exceptions.
 * Preserve useful exception context without exposing secrets, personal data, or internal details in logs, APIs, or user-facing errors.
 * Use structured logging and avoid excessive logging, especially in hot paths. Never log credentials, tokens, or sensitive payloads.
-* Keep authorization, certificate validation, encryption, and other security controls intact. Follow the focused security rules for the affected boundary.
-* Keep side effects explicit and deterministic where practical; propagate cancellation and dispose owned resources correctly.
+* Dispose owned resources correctly, including on failure paths.
 * Use narrow exception handling around the operation that can fail. Do not catch broadly merely to retry, continue with partial state, or convert failures into success.
 * Avoid returning different error detail to unauthenticated callers when it would disclose whether protected accounts, records, or resources exist.
-* Treat resource limits as part of safe error handling: cap request bodies, decompressed data, collection sizes, parser depth, and other attacker-controlled work.
+* Treat resource limits as part of safe error handling: cap request bodies, page sizes, query complexity, decompressed data, collection sizes, parser depth, and other attacker-controlled work.