Plugin versions disagree across README, marketplace.json, and plugin.json

[ecv]

What needs to happen

The three places a plugin's version is written should agree. They don't, and nothing checks.

Plugin	README table	marketplace.json	plugin.json
datum-platform	1.8.0	1.0.0	1.8.2
datum-gtm	1.1.0	1.0.0	1.1.0
milo-activity	1.0.0	1.0.0	1.0.0

plugin.json is what actually installs — a fresh datum-platform install lands 1.8.2. So the README understates by two patch releases, and the marketplace catalog has never been bumped off its initial 1.0.0.

Why this matters

Anyone checking whether they're current gets a wrong answer from whichever file they happen to open. The catalog is the worst of the three, and it's the one the marketplace publishes.

The contributing docs make it structural rather than accidental: they instruct contributors to set version in both plugin.json and marketplace.json, with nothing keeping the two in sync and a third copy in the README nobody is told about. There are no git tags and no releases, so there's no fourth source to arbitrate.

Desired outcome

A plugin's version is written once and the other references are generated or validated, so drift can't reach main.

• Reconcile the current three-way drift
• Decide which file owns the version
• Add a CI check that fails a PR where the copies disagree