feat(auth): implement OAuth 2.0 authorization code flow and dynamic client registration

- Add OAuth 2.0 support with authorization code flow and dynamic client registration.
- Introduce new handlers for OAuth metadata, client registration, authorization, and token issuance.
- Enhance authentication middleware to support OAuth client credentials.
- Create in-memory stores for authorization codes and tokens.
- Update configuration to include OAuth client details.
- Ensure validation checks for OAuth clients in the configuration.

llm/memory.md

@@ -1,5 +1,7 @@
 # AMCS Memory Instructions
 
+AMCS (Avalon Memory Crystal Server) is an MCP server for capturing and retrieving thoughts, memory, and project context. It is backed by Postgres with pgvector for semantic search.
+
 You have access to an MCP memory server named AMCS.
 
 Use AMCS as memory with two scopes:
@@ -19,8 +21,8 @@ Use AMCS as memory with two scopes:
 ## Project Memory Rules
 
 - Use project memory for code decisions, architecture, TODOs, debugging findings, and context specific to the current repo or workstream.
-- Before substantial work, retrieve context with `get_project_context` or `recall_context`.
-- Save durable project facts with `capture_thought`.
+- Before substantial work, always retrieve context with `get_project_context` or `recall_context` so prior decisions inform your approach.
+- Save durable project facts with `capture_thought` after completing meaningful work.
 - Do not attach memory to the wrong project.
 
 ## Global Notebook Rules