add data packages and remove empty submodule

packages/data/tst/README.md

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+# Ternary Search Tree (TST)
+
+A persistent ternary search tree implementation in Rust using OurDB for storage.
+
+## Overview
+
+TST is a space-optimized tree data structure that enables efficient string key operations with persistent storage. This implementation provides a persistent ternary search tree that can be used for efficient string key operations, such as auto-complete, routing tables, and more.
+
+A ternary search tree is a type of trie where each node has three children: left, middle, and right. Unlike a radix tree which compresses common prefixes, a TST stores one character per node and uses a binary search tree-like structure for efficient traversal.
+
+Key characteristics:
+- Each node stores a single character
+- Nodes have three children: left (for characters < current), middle (for next character in key), and right (for characters > current)
+- Leaf nodes contain the actual values
+- Balanced structure for consistent performance across operations
+
+## Features
+
+- Efficient string key operations
+- Persistent storage using OurDB backend
+- Balanced tree structure for consistent performance
+- Support for binary values
+- Thread-safe operations through OurDB
+
+## Usage
+
+Add the dependency to your `Cargo.toml`:
+
+```toml
+[dependencies]
+tst = { path = "../tst" }
+```
+
+### Basic Example
+
+```rust
+use tst::TST;
+
+fn main() -> Result<(), tst::Error> {
+    // Create a new ternary search tree
+    let mut tree = TST::new("/tmp/tst", false)?;
+    
+    // Set key-value pairs
+    tree.set("hello", b"world".to_vec())?;
+    tree.set("help", b"me".to_vec())?;
+    
+    // Get values by key
+    let value = tree.get("hello")?;
+    println!("hello: {}", String::from_utf8_lossy(&value)); // Prints: world
+    
+    // List keys by prefix
+    let keys = tree.list("hel")?; // Returns ["hello", "help"]
+    println!("Keys with prefix 'hel': {:?}", keys);
+    
+    // Get all values by prefix
+    let values = tree.getall("hel")?; // Returns [b"world", b"me"]
+    
+    // Delete keys
+    tree.delete("help")?;
+    
+    Ok(())
+}
+```
+
+## API
+
+### Creating a TST
+
+```rust
+// Create a new ternary search tree
+let mut tree = TST::new("/tmp/tst", false)?;
+
+// Create a new ternary search tree and reset if it exists
+let mut tree = TST::new("/tmp/tst", true)?;
+```
+
+### Setting Values
+
+```rust
+// Set a key-value pair
+tree.set("key", b"value".to_vec())?;
+```
+
+### Getting Values
+
+```rust
+// Get a value by key
+let value = tree.get("key")?;
+```
+
+### Deleting Keys
+
+```rust
+// Delete a key
+tree.delete("key")?;
+```
+
+### Listing Keys by Prefix
+
+```rust
+// List all keys with a given prefix
+let keys = tree.list("prefix")?;
+```
+
+### Getting All Values by Prefix
+
+```rust
+// Get all values for keys with a given prefix
+let values = tree.getall("prefix")?;
+```
+
+## Performance Characteristics
+
+- Search: O(k) where k is the key length
+- Insert: O(k) for new keys
+- Delete: O(k) plus potential node cleanup
+- Space: O(n) where n is the total number of nodes
+
+## Use Cases
+
+TST is particularly useful for:
+- Prefix-based searching
+- Auto-complete systems
+- Dictionary implementations
+- Spell checking
+- Any application requiring efficient string key operations with persistence
+
+## Implementation Details
+
+The TST implementation uses OurDB for persistent storage:
+- Each node is serialized and stored as a record in OurDB
+- Node references use OurDB record IDs
+- The tree maintains a root node ID for traversal
+- Node serialization includes version tracking for format evolution
+
+## Running Tests
+
+The project includes a comprehensive test suite that verifies all functionality:
+
+```bash
+cd ~/code/git.threefold.info/herocode/db/tst
+# Run all tests
+cargo test
+
+# Run specific test file
+cargo test --test basic_test
+cargo test --test prefix_test
+
+```
+
+## Running Examples
+
+The project includes example applications that demonstrate how to use the TST:
+
+```bash
+# Run the basic usage example
+cargo run --example basic_usage
+
+# Run the prefix operations example
+cargo run --example prefix_ops
+
+# Run the performance test
+cargo run --example performance
+```
+
+## Comparison with RadixTree
+
+While both TST and RadixTree provide efficient string key operations, they have different characteristics:
+
+- **TST**: Stores one character per node, with a balanced structure for consistent performance across operations.
+- **RadixTree**: Compresses common prefixes, which can be more space-efficient for keys with long common prefixes.
+
+Choose TST when:
+- You need balanced performance across all operations
+- Your keys don't share long common prefixes
+- You want a simpler implementation with predictable performance
+
+Choose RadixTree when:
+- Space efficiency is a priority
+- Your keys share long common prefixes
+- You prioritize lookup performance over balanced performance
+
+## License
+
+This project is licensed under the same license as the HeroCode project.