chore(ci): comprehensive CI/CD audit fixes per best practices

Implements all 13 fixes identified in the CI/CD audit against
github-actions-ci-cd-best-practices.instructions.md

Critical fixes:

Remove hardcoded encryption key from playwright.yml (security)
Fix artifact filename mismatch in supply-chain-pr.yml (bug)
Pin GoReleaser to ~> v2.5 instead of latest (supply chain)
High priority fixes:

Upgrade CodeQL action from v3 to v4 in supply-chain-pr.yml
Add environment protection for release workflow
Fix shell variable escaping ($$ → $) in release-goreleaser.yml
Medium priority fixes:

Add timeout-minutes to playwright.yml (20 min)
Add explicit permissions to quality-checks.yml
Add timeout-minutes to codecov-upload.yml jobs (15 min)
Fix benchmark.yml permissions (workflow-level read, job-level write)
Low priority fixes:

Add timeout-minutes to docs.yml jobs (10/5 min)
Add permissions block to docker-lint.yml
Add timeout-minutes to renovate.yml (30 min)

.github/workflows/benchmark.yml

@@ -22,14 +22,19 @@ concurrency:
 env:
   GO_VERSION: '1.25.5'
 
+# Minimal permissions at workflow level; write permissions granted at job level for push only
 permissions:
-  contents: write
-  deployments: write
+  contents: read
 
 jobs:
   benchmark:
     name: Performance Regression Check
     runs-on: ubuntu-latest
+    # Grant write permissions for storing benchmark results (only used on push via step condition)
+    # Note: GitHub Actions doesn't support dynamic expressions in permissions block
+    permissions:
+      contents: write
+      deployments: write
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6