Add Series RTL and SeriesView

Introduces a new RTL module for handling series data, enabling efficient
storage and retrieval of time-series data in a Struct-of-Arrays (SoA)
format.

Includes `SeriesView`, a zero-copy wrapper that provides a fast,
read-only interface to individual columns within a `RecordSeries`,
optimizing performance for data access in the VM.

Registers new native functions `create-series` and `push-series` for
managing series data.

src/ast/types.rs

@@ -284,6 +284,7 @@ pub enum StaticType {
     Text,
     Keyword,
     List(Box<StaticType>),               // Legacy / Dynamic list
+    Series(Box<StaticType>),             // Time series of a specific type
     Tuple(Vec<StaticType>),              // Heterogeneous fixed-size
     Vector(Box<StaticType>, usize),      // Homogeneous fixed-size
     Matrix(Box<StaticType>, Vec<usize>), // Multi-dimensional homogeneous
@@ -306,6 +307,7 @@ impl fmt::Display for StaticType {
             StaticType::Text => write!(f, "text"),
             StaticType::Keyword => write!(f, "keyword"),
             StaticType::List(inner) => write!(f, "[{}]", inner),
+            StaticType::Series(inner) => write!(f, "series<{}>", inner),
             StaticType::Tuple(elements) => {
                 write!(f, "[")?;
                 for (i, el) in elements.iter().enumerate() {
@@ -391,6 +393,10 @@ impl StaticType {
             (StaticType::Record(a), StaticType::Record(b)) => {
                 std::sync::Arc::ptr_eq(a, b)
             }
+            // Series are assignable if their inner types are assignable
+            (StaticType::Series(inner_a), StaticType::Series(inner_b)) => {
+                inner_a.is_assignable_from(inner_b)
+            }
             _ => false,
         }
     }