Store mv index on the client. Patch it from IndexUpdate. Delete MVs not in the index.

[jobelenus]

How does this PR change the system?

1. On a cold start, store the MvIndex data as an atom
2. After patches complete, we get an IndexUpdate message
3. That message now has patch data for the MvIndex itself
4. Apply that patch
5. Remove MTMs that aren't on the index

Added a fn to heimdall that will allow you to ask whether a kind & id exist on the index. This way, we can prompt the user that: "Yes—this component doesn't exist" vs "it may exist but we dont have it yet"

How was it tested?

1. Load the page
2. Use the rune menu to call Odin
3. See the MvIndex data stored
4. Go to a component detail page, remove characters from the component ID, so it will not find one, see the existence check fire without failure.
5. Make a change
6. Odin again
7. see the index checksum on the MvIndex atom is updated.
8. ensure that MTMs for HEAD are not altered

[github-actions]

Dependency Review

✅ No vulnerabilities or OpenSSF Scorecard issues found.

Scanned Files

None