feat(depot): status/push/verify/get/pull commands with exit-code contract

Adds internal/depot.Run, the stdlib-flag command surface for the five
depot subcommands (0/1/2/64/70 exit contract), plus a dispatch special
case that will route "crucible depot ..." and crucible-depot to it once
Task 6 flips Wired:true (inert for now since Wired stays false).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

internal/dispatch/dispatch.go

@@ -16,6 +16,7 @@ import (
 
 	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/app"
 	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/buildinfo"
+	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/depot"
 	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/menu"
 )
 
@@ -365,6 +366,12 @@ func runBuilder(name string, args []string, out, errw io.Writer) int {
 			return exitOK
 		}
 	}
+	if b.Name == "depot" && b.Wired {
+		// depot parses its own subcommand (status/push/verify/get/pull) and
+		// has its own richer exit contract (0/1/2/64/70), so it bypasses the
+		// b.Commands/delegateLegacy routing entirely.
+		return depot.Run(args, out, errw, os.Getenv)
+	}
 	if !b.Wired {
 		// No migrated logic yet (depot): fail closed, never fake an artifact.
 		fmt.Fprintf(errw, unwiredMsg, b.Name, b.Bin)