update claude and readme

CLAUDE.md

@@ -15,9 +15,6 @@ go build ./cmd/...
 go test ./...
 
 # Run tests for a specific package
-go test ./pkg/toughswitch/...
-
-# Run a single test
 go test ./pkg/toughswitch/... -run TestClient_AddDel
 
 # Tidy module dependencies
@@ -26,17 +23,17 @@ go mod tidy
 
 ## Architecture
 
-This repository provides Go client libraries for interacting with Ubiquiti network devices via reverse-engineered REST APIs.
+This repository provides Go client libraries for interacting with Ubiquiti network devices via reverse-engineered REST APIs, plus a CLI tool.
 
 ### Package Structure
 
 - `pkg/toughswitch/` - Client for ToughSwitch devices (e.g., TS-8-PRO)
 - `pkg/edgeos/` - Client for EdgeOS devices (EdgeRouter, EdgeSwitch)
-- `cmd/` - Optional CLI tool using cobra (work in progress)
+- `cmd/` - CLI tool using cobra
 
-### Client Design Pattern
+### Library Client Design Pattern
 
-Both packages follow the same multi-device client pattern:
+Both `pkg/toughswitch` and `pkg/edgeos` follow the same multi-device client pattern:
 
 1. **Client** - Top-level struct holding a map of `deviceClient` instances keyed by host
 2. **deviceClient** - Per-device HTTP client with authentication state (token for ToughSwitch, cookies for EdgeOS)
@@ -45,16 +42,28 @@ Both packages follow the same multi-device client pattern:
 Key characteristics:
 - Thread-safe: Uses `sync.RWMutex` for device map access and `sync.Mutex` for per-device operations
 - Auto-login: Automatically authenticates on 401 responses and retries the request
+- Explicit login: `Login(ctx, host)` can be called to pre-authenticate
 - Concurrent multi-device: `GetAll*` methods use `sync.WaitGroup.Go()` for parallel queries
 
-### API Pattern
-
-Each package exposes:
+API pattern for each package:
 - `MustNew(ctx, []Config)` - Constructor that accepts multiple device configs
+- `Login(ctx, host)` - Explicit authentication (also happens automatically on 401)
 - `Add(cfg)` / `Del(host)` - Dynamic device management
 - `Get<Resource>(ctx, host)` - Single device query
 - `GetAll<Resources>(ctx)` - Parallel query across all devices, returns `map[string]*Resource`
 
+### CLI Architecture (`cmd/`)
+
+The CLI uses cobra with a prerun chain pattern:
+
+- `cmd/cmd/root.go` - Root command with `PersistentPreRunE` hook
+- `cmd/cmd/prerun.go` - Prerun functions executed in order: `validateConfigFile` → `prepareConfig` → `prepareLogger` → `setEnvironment` → `prepareClients`
+- `cmd/cmd/client.go` - Shared `fetchDevice()` helper that retrieves clients from context
+- `cmd/internal/util/context.go` - Context helpers for config, logger, and clients
+- `cmd/internal/config/config.go` - Config loading from YAML/JSON files with env overlay
+
+Context flow: Prerun creates clients based on config and stores them in context. Commands retrieve clients via `util.ToughSwitchClientFromContext(ctx)` / `util.EdgeOSClientFromContext(ctx)`.
+
 ### Authentication
 
 - **ToughSwitch**: Token-based via `x-auth-token` header from `/api/v1.0/user/login`