Add API tokens, CLI server API and shared core crate

- Personal API tokens (full/read scope, expiry, revoke) and CLI password login
- Cargo workspace: codecraft-core (types, providers, permission rules) shared by
  server and the upcoming terminal client; server re-exports the old paths
- CLI server API: /cli/config, /cli/skill, /cli/tool (server MCP tools),
  /llm/stream model gateway with budgets and usage per user
- Theme/language preferences mirrored to the server; personal memory endpoint
- Statistics: provider and mode tables stacked; CLI usage labelled
- cli/: work in progress (terminal client is being rewritten as a local TUI)

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

core/src/lib.rs

@@ -0,0 +1,7 @@
+//! Shared core of CodeCraft (server and command line client): message types,
+//! model providers (Anthropic, OpenAI-compatible) and permission rules.
+
+pub mod config;
+pub mod permission;
+pub mod provider;
+pub mod types;