This commit introduces a new data server module (`src/ast/data_server`)
designed for high-performance, thread-safe loading and caching of market
data.
Key components:
- `DataServer`: Manages symbol indexing and delegates loading/caching.
- `SymbolIndex`: Scans the data directory and maintains a sorted index
of data files per symbol.
- `FileCache`: Implements a thread-safe cache using `RwLock` and a
loading guard to prevent duplicate work.
- `loader`: Handles ZIP decompression and binary record parsing from
`.bin` files.
- `records`: Defines raw and parsed data structures for M1 and tick
data.
- `SymbolChunkIter`: Provides an iterator over pre-parsed data chunks,
prefetching subsequent files.
This architecture allows multiple VM threads to access market data
concurrently without redundant I/O, mirroring the strategy used in the
original Delphi `TDataServer`.
