Feature integration test sharding

[vfusco]

No description provided.

[Copilot]

Pull request overview

This PR introduces integration-test sharding to speed up CI by splitting the integration suite into isolated Docker Compose projects, plus adds supporting tooling (log capture, shard coverage guard) and updates workflows/actions accordingly.

Changes:

• Add shard-aware integration test execution (Makefile shards + TEST_PATTERN forwarding) and a shard coverage guard for CI.
• Introduce a Compose runner script that captures run output + node log + service logs per shard into dedicated artifacts.
• Replace the GitHub license-header action with a repo-local license header verification script; update CI workflows and housekeeping.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
test/integration/main_test.go	Skips node management when invoked via go test -list to support shard discovery.
test/compose/compose.integration.yaml	Adds shard/test selection env vars and gotestsum format configuration for the integration container.
scripts/run-integration-tests.sh	Adds TEST_PATTERN/SHARD_NAME support and centralizes Go test args for shard runs.
scripts/compose-integration-run.sh	New: isolated Compose project runner that aggregates logs into a single file per run/shard.
scripts/check-license-header.sh	New: checks Go source files for the standard license header (replacing the previous action).
scripts/check-integration-shards.sh	New: validates that every top-level integration test belongs to exactly one shard.
README.md	Minor wording/link formatting tweak.
Makefile	Adds shard definitions/targets, log cleanup target, and license check target; updates integration CI plumbing.
Dockerfile	Installs additional binutils packages needed for build/linking.
.gitignore	Ignores integration log artifacts.
.github/workflows/clean-up-images.yml	Switches GHCR cleanup to a scheduled workflow and pins the prune action by commit.
.github/workflows/build.yml	Updates actions, adds shard-matrix integration job setup, and uploads per-shard logs.
.github/license-check/config.json	Removed (no longer needed after switching to the local license header script).

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