feat(params): accept --limitGenomeGenerateRAM for STAR CLI compatibility

STAR exposes --limitGenomeGenerateRAM as a memory cap for genomeGenerate.
Pipelines that wrap STAR commonly derive a value from their task resources
and pass it through. Currently rustar rejects the flag at the CLI parser,
breaking those pipelines.

Accept the flag with STAR's default of 31 GiB. The value is parsed but not
enforced — rustar's memory management is independent.

Fixes #25

Author: pinin4fjords

src/params.rs

@@ -363,6 +363,12 @@ pub struct Parameters {
     #[arg(long = "limitBAMsortRAM", default_value_t = 0)]
     pub limit_bam_sort_ram: u64,
 
+    /// Maximum available RAM (bytes) for genome generation.
+    ///
+    /// Accepted for STAR CLI compatibility. Not currently enforced — rustar uses its own memory management.
+    #[arg(long = "limitGenomeGenerateRAM", default_value_t = 31_000_000_000_u64)]
+    pub limit_genome_generate_ram: u64,
+
     /// Route primary alignment output to stdout instead of a file.
     /// Values: None (default), SAM, BAM_Unsorted, BAM_SortedByCoordinate.
     #[arg(long = "outStd", default_value = "None")]