Conform to Agent Plugins v1.0.0 alongside Claude Code's format

[allenhutchison]

Summary

• Adds a root-level plugin.json to each of the seven plugins, conforming to the Agent Plugins v1.0.0 open spec, alongside the existing .claude-plugin/plugin.json that Claude Code reads.
• Each plugin's skills/*/SKILL.md layout already matched the open spec's discovery rules, so no restructuring was needed there — just the manifest.
• Updates scripts/bump-version.py so the open-spec manifest's version stays in lockstep with .claude-plugin/plugin.json and the marketplace.json entry on every automated bump.
• Adds a CI check (.github/workflows/validate.yml) enforcing the spec's closed field schema and name/version agreement for any plugin that ships the open-spec manifest.
• Updates README.md's repository layout and versioning sections to describe the dual manifest.

Test plan

• python3 scripts/check-links.py — passes, no broken links
• ./scripts/sync-references.sh --check — passes
• Ran the new CI validation logic locally against all 7 plugins — passes
• ./scripts/bump-version.py --level patch core --dry-run — correctly reports the bump, confirming the script's new open-spec sync path works
• Verified all 7 generated plugin.json files parse as valid JSON and preserve literal (non-escaped) unicode from the source manifests

[greptile-apps]

Greptile Summary

The PR adds Agent Plugins v1.0.0 manifests alongside Claude Code manifests and keeps their versions synchronized through validation and bump automation.

• Adds root-level open-spec manifests for all seven plugins.
• Extends version bumping and CI validation to enforce manifest agreement.
• Fixes the automated bump workflow to stage the newly updated open-spec manifests.
• Documents the dual-manifest layout and versioning process.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains; the workflow now stages the root open-spec manifests updated by the version bump script, resolving the previously reported stale-manifest issue.

Important Files Changed

Filename	Overview
.github/workflows/version-bump.yml	The staging command now includes every root-level open-spec manifest updated by the bump script, resolving the previously reported omission.
scripts/bump-version.py	Version bumps now validate and update an optional open-spec manifest alongside the Claude and marketplace manifests.
.github/workflows/validate.yml	CI validates opted-in open-spec manifests against the closed schema and checks marketplace name/version agreement.
README.md	Documentation now explains the dual-manifest layout and synchronized versioning workflow.
plugins/core/plugin.json	Representative new Agent Plugins v1.0.0 manifest matches the core plugin’s marketplace identity and version.

_{Reviews (2): Last reviewed commit: "fix(ci): stage the open-spec plugin.json..." | Re-trigger Greptile}