Fix PR review comments

- docs/guides/solana-development.md: Use overrideAttrs instead of override to properly extend shell configuration without breaking zero.nix environment setup
- packages/solana-tools.nix: Improve idl command detection to match whole words only, preventing false positives with substrings like 'my-idl-program'

Author: hxrts

docs/guides/solana-development.md

@@ -202,7 +202,7 @@ These environment variables ensure that:
 
 ### Custom Configuration
 
-Override environment variables in your `flake.nix`:
+Extend the development environment in your `flake.nix`:
 
 ```nix
 {
@@ -211,15 +211,15 @@ Override environment variables in your `flake.nix`:
       inherit self;
       src = ./.;
       
-      devShells.default = zero-nix.devShells.default.override {
-        shellHook = ''
+      devShells.default = zero-nix.devShells.default.overrideAttrs (oldAttrs: {
+        shellHook = (oldAttrs.shellHook or "") + ''
           # Custom solana configuration
           solana config set --url https://api.mainnet-beta.solana.com
           
           # Project-specific setup
           echo "My Solana project initialized"
         '';
-      };
+      });
     };
 }
 ```
@@ -245,12 +245,12 @@ Add zero.nix to your `flake.nix`:
   };
 
   outputs = { self, zero-nix }: {
-    devShells.default = zero-nix.devShells.default.override {
-      buildInputs = with zero-nix.legacyPackages.${system}; [
+    devShells.default = zero-nix.devShells.default.overrideAttrs (oldAttrs: {
+      buildInputs = (oldAttrs.buildInputs or []) ++ (with zero-nix.legacyPackages.${system}; [
         solana-tools
         # Add your existing tools here
-      ];
-    };
+      ]);
+    });
   };
 }
 ```

packages/solana-tools.nix

@@ -329,11 +329,13 @@ EOF
     mkdir -p "$CARGO_HOME" "$RUSTUP_HOME"
     
     # Check if this is for IDL generation and use nightly rust
-    if [[ "$*" == *"idl"* ]]; then
-      export PATH="${nightly-rust}/bin:${solana-node}/bin:$PATH"
-      export RUSTC="${nightly-rust}/bin/rustc"
-      export CARGO="${nightly-rust}/bin/cargo"
-    fi
+    case " $@ " in
+      *" idl "*)
+        export PATH="${nightly-rust}/bin:${solana-node}/bin:$PATH"
+        export RUSTC="${nightly-rust}/bin/rustc"
+        export CARGO="${nightly-rust}/bin/cargo"
+        ;;
+    esac
     
     # Run anchor with platform tools environment
     exec "${anchor}/bin/anchor" "$@"