🔧 Fix rolling k-mer and minimizer logic

Fix incorrect nucleotide encoding in `rolling_k` update, correct shift amount for reverse complement k-mer (`self.k - 1`, not `k`), and rename method to match semantics. Also add proper windowed minimizer cleanup when received length exceeds k.

src/obiskbuilder/src/rolling_stat.rs

@@ -85,9 +85,9 @@ impl RollingStat {
         let bnuc = encode_nuc(nuc as u8);
         let cnuc = bnuc ^ 3;
 
-        self.rolling_k = ((self.rolling_k << 2) | (cnuc as u64)) & self.k_mask;
+        self.rolling_k = ((self.rolling_k << 2) | (bnuc as u64)) & self.k_mask;
         self.rolling_rck =
-            ((self.rolling_rck >> 2) | ((cnuc as u64) << (self.k * 2))) & self.k_mask;
+            ((self.rolling_rck >> 2) | ((cnuc as u64) << ((self.k -1) * 2))) & self.k_mask;
 
 
         let canonical_k1 = entropy_norm_kmer(self.rolling_k & 3, 1, false);
@@ -108,6 +108,12 @@ impl RollingStat {
                 self.minimier.pop_back();
             }
             self.minimier.push_back(MmerItem { position: possible_pos_m, canonical: possible_canonical_m });
+
+            if self.received > self.k {
+                while self.minimier.front().map_or(false, |it| it.position + self.k <= self.received) {
+                    self.minimier.pop_front();
+                }
+            }
         }
 
         if self.received > self.k {
@@ -180,9 +186,9 @@ impl RollingStat {
         }
     }
 
-    pub fn minimizer_canonical(&self) -> Option<Kmer> {
+    pub fn canonical_minimizer(&self) -> Option<Kmer> {
         if self.ready() {
-            self.minimier.front().map(|it| Kmer::from_raw_right(it.canonical, self.k))
+            self.minimier.front().map(|it| Kmer::from_raw_right(it.canonical, self.m))
         } else {
             None
         }