docs: add module documentation in AsciiDoc with PlantUML diagrams

Generated by per-group subagents covering all 52 modules across:
core (18), infrastructure (10), apps (5), interfaces (3),
plugins (7), testing (9)

Documentation format:
- AsciiDoc (.adoc) files in docs/modules/<group>/
- PlantUML (.puml) files in docs/diagrams/
- .adoc files reference diagrams via include:: directives

Each doc covers: purpose, responsibilities, non-responsibilities,
key types, event flow, integration points, invariants, PlantUML
diagram, known issues, and open questions.

docs/diagrams/infra-inference-llama-cpp.puml

@@ -0,0 +1,28 @@
+@startuml
+!theme plain
+package "infra-inference-llama-cpp" {
+  class LlamaCppInferenceProvider
+  class DefaultModelManager
+  class DefaultManagedInferenceProvider
+  class LlamaProcess
+  class LlamaCppTokenizer
+  class GbnfGrammarConverter
+  package "LlamaCppApiModels" {
+    class ChatCompletionRequest
+    class ChatCompletionResponse
+    class ChatMessage
+  }
+}
+interface InferenceProvider <<core:inference>>
+interface ModelManager <<infra-inference-commons>>
+interface ManagedInferenceProvider <<infra-inference-commons>>
+InferenceProvider <|.. LlamaCppInferenceProvider
+ManagedInferenceProvider <|.. DefaultManagedInferenceProvider
+DefaultManagedInferenceProvider --> LlamaCppInferenceProvider : delegates to
+ModelManager <|.. DefaultModelManager
+DefaultModelManager *--> LlamaProcess : manages
+LlamaCppInferenceProvider --> LlamaCppTokenizer : uses
+LlamaCppInferenceProvider --> GbnfGrammarConverter : uses
+DefaultModelManager --> LlamaCppInferenceProvider : creates
+GbnfGrammarConverter --> ChatCompletionRequest : generates grammar for
+@enduml