Fix crates.io secret name: CRATES_IO_TOKEN -> CARGO_REGISTRY_TOKEN

The repository secret is named CARGO_REGISTRY_TOKEN, but four references
across release-all.yml and publish-crates.yml read secrets.CRATES_IO_TOKEN,
which does not exist. GitHub resolves a missing secret to an empty string
rather than failing, so cargo received "" and the v1.0.4 release died with:

  error: failed to publish ison-rs v1.0.2 to registry at https://crates.io
  Caused by:
    please provide a non-empty token

The wrong name was inherited from the original workflow and carried through
the rewrite without being checked against the actual secret list. Every
secrets.* reference across all workflows now resolves to a configured secret:
CARGO_REGISTRY_TOKEN, GITHUB_TOKEN, NPM_TOKEN, PYPI_API_TOKEN.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: maheshvaikri-code

.github/workflows/publish-crates.yml

@@ -45,7 +45,7 @@ jobs:
         if: ${{ inputs.dry_run != true }}
         working-directory: ison-rust
         env:
-          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
         run: cargo publish
 
       - name: Dry run
@@ -84,7 +84,7 @@ jobs:
         if: ${{ inputs.dry_run != true }}
         working-directory: isonantic-rust
         env:
-          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
         run: cargo publish
 
       - name: Dry run

.github/workflows/release-all.yml

@@ -279,7 +279,7 @@ jobs:
             cargo publish
           fi
         env:
-          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
 
   # ===========================================
   # PHASE 3: Publish Dependent Packages
@@ -307,7 +307,7 @@ jobs:
             cargo publish
           fi
         env:
-          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
 
   # ===========================================
   # PHASE 4: Create Release