Allow musl cross interpreters to load C dependencies

Keep static Haskell libraries and fully static application outputs while planning ghc914-sh iserv projects with a dynamic musl C loader. Scope the policy to Linux-built musl Cabal v2 interpreters and check that scope in static Linux CI.

Normal and profiled target plans preserve all unit IDs, source records and Haskell ways; only the iserv executable-static flag changes. The shared V2 project skeleton changes auxiliary derivation hashes. A small i686 musl probe reproduces static dlopen failure and verifies the dynamic loader under QEMU; full interpreter TH validation remains for canonical CI.

.github/workflows/nix.yml

@@ -93,6 +93,11 @@ jobs:
         timeout-minutes: 1
         run: nix eval --json --file scripts/nix/check-android-iserv-scope.nix
 
+      - name: Check musl interpreter link policy scope
+        if: ${{ matrix.target == 'linux-static' }}
+        timeout-minutes: 1
+        run: nix eval --json --file scripts/nix/check-musl-iserv-scope.nix
+
       - name: Check native Linux GHC ELF section alignment
         if: ${{ matrix.system == 'x86_64-linux' && matrix.target == 'native' }}
         timeout-minutes: 120