refactor: chats method shebangs; drop chats index (D14).

Parsers and commands live in internal/chats. bin/chats/{sync,import,facts,apply}.go
are tagged shebang mains. Brain ingest is not a chats command.

bin/chats/sync.go

@@ -0,0 +1,41 @@
+//usr/bin/env go run -tags=chats_sync "$0" "$@"; exit
+//go:build chats_sync
+//
+// bin/chats/sync.go - download chat messages to var/chats/<platform>/.
+//
+//	./bin/chats/sync.go telegram [--limit N] [--phone PHONE]
+//	./bin/chats/sync.go linkedin [--limit N] [--refresh]
+//
+// NOTE: never run `gofmt -w` on this file — it breaks the shebang.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/eSlider/2dph/internal/chats"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, `usage: bin/chats/sync.go telegram|linkedin [flags]`)
+		os.Exit(2)
+	}
+	platform := os.Args[1]
+	args := os.Args[2:]
+	switch platform {
+	case "telegram":
+		os.Exit(chats.RunSyncTelegram(args))
+	case "linkedin":
+		os.Exit(chats.RunSyncLinkedIn(args))
+	case "whatsapp":
+		fmt.Fprintln(os.Stderr, "chats: WhatsApp not implemented yet")
+		os.Exit(1)
+	case "help", "-h", "--help":
+		fmt.Fprintln(os.Stderr, `usage: bin/chats/sync.go telegram|linkedin [flags]`)
+		return
+	default:
+		fmt.Fprintf(os.Stderr, "chats: unknown platform %q\n", platform)
+		os.Exit(2)
+	}
+}