Migrate internal architecture docs to docs/internal

docs/architecture.md

@@ -1,14 +1,16 @@
 # Audita Architecture Index
 
-This file is the entrypoint for architecture documentation.
+This file is the architecture documentation entrypoint.
 
-Core architecture overview:
-- [Architecture Overview](./architecture/architecture.md)
+Implemented internals:
+- [Internal Overview](./internal/overview.md)
+- [Pipeline](./internal/pipeline.md)
+- [Modules](./internal/modules.md)
+- [Validators](./internal/validators.md)
+- [LLM Runtime](./internal/llm-runtime.md)
+- [Diagnostics and Reporting](./internal/diagnostics-reporting.md)
+- [Prompts](./internal/prompts.md)
+- [Output Schemas](./internal/output-schemas.md)
 
-Focused architecture contracts:
+External/runtime contract summary:
 - [Public Contract](./architecture/public-contract.md)
-- [Diagnostics](./architecture/diagnostics.md)
-- [Structured LLM](./architecture/structured-llm.md)
-- [Validators](./architecture/validators.md)
-- [Prompts](./architecture/prompts.md)
-- [Output Schemas](./architecture/output-schemas.md)