[.github/workflows/ci-cargo.yml] Add missing rustfmt ; [README.md] Newline break in mermaid

Author: SamuelMarks

.github/workflows/ci-cargo.yml

@@ -20,7 +20,9 @@ jobs:
       - uses: actions/checkout@v6
 
       - name: Set up Rust
-        run: rustup override set nightly
+        run: |
+          rustup override set nightly
+          rustup component add rustfmt
 
       - name: Check Formatting
         run: cargo fmt -- --check

README.md

@@ -32,7 +32,7 @@ graph TD
     DB[(Database)]:::navy
 
 %% Flow 0 & 1: Downward (Scaffold & Patch)
-    OpenAPI -->|"0. Scaffold (New) | 1. Patch (Existing)"| Handlers
+    OpenAPI -->|"0. Scaffold (New) |<br/> 1. Patch (Existing)"| Handlers
 
 %% Connection
     Handlers -- "Uses Strictly Typed Structs" --> Models