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>

server/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2024"
 description = "Web-based coding harness for AI models"
 
 [dependencies]
+codecraft-core = { path = "../core" }
 anyhow = "1"
 argon2 = "0.6"
 sha2 = "0.11"