docs: improve CLI help, shell completion, and README

- Add command groups (Getting Started, Search, Downloads, Daemon, System)
- Add shell completion command (bash, zsh, fish, powershell)
- Add flag completions for --type, --quality, --sort, --lang, --genre,
  --country, --method, --player
- Improve Long descriptions and Examples for all commands
- Split doctor disk check into platform-specific files (Unix/Windows)
- Validate infoHash length before truncating (prevent panic)
- Fix references to non-existent 'unarr daemon start' command
- Move stats command to System & Diagnostics group
- Rewrite README with complete documentation, correct config format
  (toml not yaml), all commands, shell completion section

internal/cmd/reload_unix.go

@@ -0,0 +1,53 @@
+//go:build !windows
+
+package cmd
+
+import (
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/torrentclaw/torrentclaw-cli/internal/agent"
+	"github.com/torrentclaw/torrentclaw-cli/internal/config"
+)
+
+// ReloadableConfig holds a reference to the daemon for hot-reload.
+type ReloadableConfig struct {
+	Daemon *agent.Daemon
+}
+
+// startReloadWatcher listens for SIGUSR1 and reloads config.
+// Only intervals are hot-reloadable (speeds require torrent client restart).
+func startReloadWatcher(rc *ReloadableConfig) {
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGUSR1)
+
+	go func() {
+		for range sigCh {
+			log.Println("Received SIGUSR1, reloading config...")
+
+			cfg, err := config.Load("")
+			if err != nil {
+				log.Printf("Config reload failed: %v", err)
+				continue
+			}
+			cfg.ApplyEnvOverrides()
+
+			// Update poll interval
+			if d, _ := time.ParseDuration(cfg.Daemon.PollInterval); d > 0 && rc.Daemon.PollTicker != nil {
+				rc.Daemon.PollTicker.Reset(d)
+				log.Printf("  Poll interval: %s", d)
+			}
+
+			// Update heartbeat interval
+			if d, _ := time.ParseDuration(cfg.Daemon.HeartbeatInterval); d > 0 && rc.Daemon.HeartbeatTicker != nil {
+				rc.Daemon.HeartbeatTicker.Reset(d)
+				log.Printf("  Heartbeat interval: %s", d)
+			}
+
+			log.Println("Config reloaded successfully")
+		}
+	}()
+}