feat: persist and dispatch client command input

internal/client/spool/spool.go

@@ -37,18 +37,23 @@ type Options struct {
 	BusyTimeout    time.Duration
 	TombstoneLimit uint64
 	QuotaLimits    QuotaLimits
-	MaxScriptBytes uint64
+	// MaxExecutionSpecBytes bounds the decompressed protobuf retained for an
+	// accepted command. It is separate from MaxScriptBytes because a script
+	// body is uploaded in a different table and lifecycle.
+	MaxExecutionSpecBytes uint64
+	MaxScriptBytes        uint64
 }
 
 type Store struct {
-	db             *sql.DB
-	unlock         func() error
-	dataDir        string
-	identity       domain.UUID
-	tombstoneLimit uint64
-	quotaLimits    QuotaLimits
-	maxScriptBytes uint64
-	mu             sync.Mutex
+	db                    *sql.DB
+	unlock                func() error
+	dataDir               string
+	identity              domain.UUID
+	tombstoneLimit        uint64
+	quotaLimits           QuotaLimits
+	maxScriptBytes        uint64
+	maxExecutionSpecBytes uint64
+	mu                    sync.Mutex
 }
 
 // Open recovers an existing spool or creates an empty one. The caller must
@@ -76,6 +81,15 @@ func Open(ctx context.Context, options Options) (*Store, error) {
 			options.MaxScriptBytes = options.QuotaLimits.CommandTotalBytes
 		}
 	}
+	if options.MaxExecutionSpecBytes == 0 {
+		options.MaxExecutionSpecBytes = 768 << 10
+		if options.MaxExecutionSpecBytes > options.QuotaLimits.CommandTotalBytes {
+			options.MaxExecutionSpecBytes = options.QuotaLimits.CommandTotalBytes
+		}
+	}
+	if options.MaxExecutionSpecBytes > options.QuotaLimits.CommandTotalBytes {
+		return nil, errors.New("execution specification maximum exceeds client command quota")
+	}
 	if options.MaxScriptBytes > options.QuotaLimits.CommandTotalBytes {
 		return nil, errors.New("script maximum exceeds client command quota")
 	}
@@ -110,7 +124,7 @@ func Open(ctx context.Context, options Options) (*Store, error) {
 	}
 	db.SetMaxOpenConns(1)
 	db.SetMaxIdleConns(1)
-	store := &Store{db: db, unlock: unlock, dataDir: options.DataDir, identity: identity, tombstoneLimit: options.TombstoneLimit, quotaLimits: options.QuotaLimits, maxScriptBytes: options.MaxScriptBytes}
+	store := &Store{db: db, unlock: unlock, dataDir: options.DataDir, identity: identity, tombstoneLimit: options.TombstoneLimit, quotaLimits: options.QuotaLimits, maxScriptBytes: options.MaxScriptBytes, maxExecutionSpecBytes: options.MaxExecutionSpecBytes}
 	if err := db.PingContext(ctx); err != nil {
 		_ = store.Close()
 		return nil, fmt.Errorf("open client spool SQLite: %w", err)