feat: implement core CLI packages and Phase 3 commands

- config: resolve binary dir, load/save .hf-config.json
- mode: detect padded-cell vs manual mode via pass_mgr
- client: HTTP client wrapper with auth header support
- passmgr: pass_mgr integration (get-secret, set, generate)
- output: human-readable + JSON output formatting with tables
- help: help and help-brief renderer for groups/commands
- commands: version, health, config (--url, --acc-mgr-token, show)
- auth: token resolution helper (padded-cell auto / manual explicit)
- main: command dispatcher with --json global flag support
- README: updated with current package layout and status

internal/commands/config.go

@@ -0,0 +1,53 @@
+package commands
+
+import (
+	"fmt"
+
+	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/config"
+	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/mode"
+	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/output"
+	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/passmgr"
+)
+
+// RunConfigURL sets the base URL in the config file.
+func RunConfigURL(url string) {
+	if url == "" {
+		output.Error("usage: hf config --url <hf-url>")
+	}
+	if err := config.UpdateURL(url); err != nil {
+		output.Errorf("failed to update config: %v", err)
+	}
+	fmt.Printf("base-url set to %s\n", url)
+}
+
+// RunConfigAccMgrToken stores the account-manager token via pass_mgr.
+func RunConfigAccMgrToken(token string) {
+	if token == "" {
+		output.Error("usage: hf config --acc-mgr-token <token>")
+	}
+	if !mode.IsPaddedCell() {
+		output.Error("--acc-mgr-token can only be set with padded-cell plugin")
+	}
+	if err := passmgr.SetAccountManagerToken(token); err != nil {
+		output.Errorf("failed to store acc-mgr-token: %v", err)
+	}
+	fmt.Println("account-manager token stored successfully")
+}
+
+// RunConfigShow displays the current config.
+func RunConfigShow() {
+	cfg, err := config.Load()
+	if err != nil {
+		output.Errorf("config error: %v", err)
+	}
+	if output.JSONMode {
+		output.PrintJSON(cfg)
+	} else {
+		p, _ := config.ConfigPath()
+		output.PrintKeyValue(
+			"base-url", cfg.BaseURL,
+			"config-file", p,
+			"mode", mode.Detect().String(),
+		)
+	}
+}