ci: package releases in parallel with the verify jobs; only the draft job waits for both

The release job (the only one that signs SHA256SUMS.txt or touches a GitHub Release) now needs
every verify and packaging job; packaging no longer waits for verify. Verify jobs restore
develop's CI caches through shared keys (same CARGO_* env as ci.yml); saving stays main-only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

.github/workflows/ci.yml

@@ -129,6 +129,8 @@ jobs:
           targets: wasm32-unknown-unknown
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
+          # Shared keys: release.yml's verify jobs restore these caches (they save only on main).
+          shared-key: ci
           save-if: ${{ github.ref == 'refs/heads/develop' }}
       - name: cargo xtask ci (the affected crates, or everything)
         env:
@@ -149,6 +151,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
+          shared-key: heavy
           save-if: ${{ github.ref == 'refs/heads/develop' }}
       - run: cargo xtask test --heavy
 
@@ -167,7 +170,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
-          key: oracle
+          shared-key: oracle
           save-if: ${{ github.ref == 'refs/heads/develop' }}
       - run: cargo xtask oracle
       - name: docs/oracle.md is current
@@ -185,7 +188,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
-          key: oracle-macos
+          shared-key: oracle-macos
           save-if: ${{ github.ref == 'refs/heads/develop' }}
       - run: cargo xtask oracle
       - name: docs/oracle.md is current