Update core-architecture.mermaid.md

Author: t81dev

docs/diagrams/core-architecture.mermaid.md

@@ -1,30 +1,36 @@
 ```mermaid
 flowchart LR
-    subgraph Core [t81::core]
-        limb[l1:limb (48 trits)]
-        bigint[bigint (limb slices)]
-    end
-    subgraph HighLevel [Umbrella helpers]
-        Int[t81::Int]
-        Float[t81::Float / FloatN]
-        BigInt[t81::BigInt alias]
-        Ratio[t81::Ratio]
-        Vector[t81::Vector]
-    end
-    limb --> Int
-    limb --> Float
-    bigint --> BigInt
-    BigInt --> Ratio
-    Vector --> Float
-    Float --> Ratio
-    Vector --> Int
-    subgraph Ops [Arithmetic & GEMM]
-        GEMM[t81::linalg::gemm_ternary]
-        Fixed[t81::Fixed<N>]
-    end
-    Int --> Ops
-    Float --> Ops
-    Vector --> GEMM
-    Fixed --> GEMM
-    click Float "docs/api-overview.md" "See the helper summary"
+  subgraph Core["t81::core"]
+    limb["l1: limb (48 trits)"]
+    bigint["bigint (limb slices)"]
+  end
+
+  subgraph HighLevel["Umbrella helpers"]
+    Int["t81::Int"]
+    Float["t81::Float / FloatN"]
+    BigInt["t81::BigInt alias"]
+    Ratio["t81::Ratio"]
+    Vector["t81::Vector"]
+  end
+
+  subgraph Ops["Arithmetic & GEMM"]
+    GEMM["t81::linalg::gemm_ternary"]
+    Fixed["t81::Fixed<N>"]
+  end
+
+  limb --> Int
+  limb --> Float
+  bigint --> BigInt
+  BigInt --> Ratio
+  Vector --> Float
+  Float --> Ratio
+  Vector --> Int
+
+  Int --> GEMM
+  Float --> GEMM
+  Vector --> GEMM
+  Fixed --> GEMM
+
+  %% GitHub-safe click: use repo-relative path (or a full URL)
+  click Float "./docs/api-overview.md" "See the helper summary"
 ```