orpc-v2: migrate apps and votes plugins to the new plugin API

[elliotBraem]

Ticket ID: B4c

Parent

#248 — orpc-v2: consolidate fork into everything-dev and migrate platform to oRPC v2 + Effect 4 (epic)

What to build

Stage B, step 4c: migrate the apps plugin (registry discovery, FastKV app metadata) and the votes plugin to the new createPlugin API. Both keep serving identical routes and responses.

Acceptance criteria

• Both plugins' test suites green on the new API
• Registry listing and votes routes serve identical responses (spot-diff against pre-migration)

Blocked by

• orpc-v2: createPlugin restructure (Layer-based initialize, errorStatusMap, scope lifecycle) #259 — createPlugin restructure
• orpc-v2: migrate all six contracts to the v2 route builder #260 — migrate all six contracts to the v2 route builder