chore: update CozyStack upstream to e26894e

[kingdonb]

🤖 Automated CozyStack Dependency Update

This PR automatically updates our CozyStack upstream dependency.

Changes:

• Updated upstream commit to: e26894e
• Upstream date: 2026-04-17T19:11:47Z
• Patch compatibility: failure ✅

Recent Upstream Changes

e26894e7 [Backport release-1.3] fix(linstor): restrict linstor-gui to cozystack-cluster-admin group (#2419)
2461c239 fix(linstor): restrict linstor-gui to cozystack-cluster-admin group
4053fad9 [apps] feat(bucket): add WorkloadMonitor and BucketClaim tracking to controller (#2391)
3803e6e0 fix(controller): use dedicated HTTP client instead of http.DefaultClient
c72fadec fix(controller): scope Prometheus query to only matched bucket names
8183b466 perf(controller): skip Prometheus calls when no BucketClaims matched
475d24b0 perf(controller): batch all bucket metrics into single Prometheus query
ed9808fa perf(controller): resolve Prometheus URL once per reconcile, not per BucketClaim
260ce84e fix(controller): distinguish empty buckets from monitoring unavailable
a6f74f31 refactor(controller): remove s3-buckets count resource from bucket workloads

⚠️ Potential Breaking Changes Detected:

e26894e7 [Backport release-1.3] fix(linstor): restrict linstor-gui to cozystack-cluster-admin group (#2419)
53ba9987 Update README.md (#2409)
c87cccae docs: adopt Conventional Commits for commit and PR titles (#2395)
be40ac55 fix(api): tighten tenant name regex and add regression guards

🧪 Pre-flight Checks

• Upstream commit retrieved successfully
• Patch compatibility tested
• ⚠️ Patch conflicts detected - manual review required

🚀 Next Steps

1. Review the upstream changes above
2. Verify CI pipeline passes with new upstream
3. Test ARM64 build with new CozyStack version
4. Merge when ready

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This PR was automatically created by the dependency update workflow