feat(09-05): add recon full/list commands and remove stub

- cmd/recon.go owns reconCmd with full and list subcommands
- Wires pkg/recon.Engine.SweepAll + Dedup with ExampleSource registered
- Adds --stealth, --respect-robots (default true), --query flags
- Removes reconCmd stub from cmd/stubs.go

cmd/stubs.go

@@ -21,11 +21,7 @@ var verifyCmd = &cobra.Command{
 	RunE:  notImplemented("verify", "Phase 5"),
 }
 
-var reconCmd = &cobra.Command{
-	Use:   "recon",
-	Short: "Run OSINT recon across internet sources (Phase 9+)",
-	RunE:  notImplemented("recon", "Phase 9"),
-}
+// reconCmd is implemented in cmd/recon.go (Phase 9).
 
 // keysCmd is implemented in cmd/keys.go (Phase 6).