ci(release): scope cache key hashFiles to root package-lock.json

The Post Cache Cypress binary step in the prepare job was failing because
hashFiles('**/package-lock.json') re-evaluates after the job runs, by which
point the workspace contains node_modules, generated docs, and worktree
leftovers from JamesIves/github-pages-deploy-action. Recursing across all
of that made hashFiles fail with "The template is not valid".

Use the root-scoped package-lock.json (only one exists in this repo) for
both the Cypress binary cache and the Vite build cache keys.

Agent-Logs-Url: https://github.com/Hack23/blacktrigram/sessions/ebbb6ddd-5533-4b82-a333-de9f0299ca5a

Co-authored-by: pethers <1726836+pethers@users.noreply.github.com>

Author: Copilot

.github/workflows/release.yml

@@ -91,7 +91,7 @@ jobs:
         uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
           path: ~/.cache/Cypress
-          key: v2-cypress-${{ runner.os }}-${{ hashFiles('**/package-lock.json') }}
+          key: v2-cypress-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
           restore-keys: |
             v2-cypress-${{ runner.os }}-
 
@@ -203,7 +203,7 @@ jobs:
         uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
           path: node_modules/.vite
-          key: v2-${{ runner.os }}-vite-${{ hashFiles('**/package-lock.json') }}
+          key: v2-${{ runner.os }}-vite-${{ hashFiles('package-lock.json') }}
           restore-keys: |
             v2-${{ runner.os }}-vite-