## What changed
- Use V2 discovery inventories for plugin MCP contributions when supplied, including empty or failed inventories; retain legacy discovery when no V2 snapshot is supplied.
- Merge plugins by canonical identity, using cloud metadata and enablement for remote plugins and attaching executor installations only when versions match. Preserve configured executor-local plugins and executor enablement when cloud data is unavailable.
- Keep installation order stable across refreshes and run merged MCP declarations on the first retained executor installation while preserving attribution for the others.
- Carry local and remote identities through selected-plugin snapshots, skill attribution, and active-plugin telemetry. Track disabled plugin IDs alongside disabled roots.
- Preserve a complete cloud catalog when a partial refresh arrives, and cap tool-description plugin attribution at 1,024 bytes while retaining all plugin associations.
## Testing
Add coverage for catalog parsing and reconciliation, enablement and discovery-mode selection, installation refresh ordering, executor-specific MCP normalization, selected-plugin snapshots, and bounded UTF-8 attribution text.
GitOrigin-RevId: a8ad352de6a2b8dc4bfd1ff6a5c62ee8ed1d1664
## What changed
- Define `capabilities/discoverV2` request and inventory types and advertise `capabilityDiscoveryV2` in executor metadata.
- Prewarm installed plugin and global skill locations at server startup, with nonfatal scan failures.
- Add sandbox-scoped discovery caching with file watcher invalidation and request-time reloads when watching is unavailable.
- Batch metadata reads through the filesystem sandbox helper and bound discovery responses to 4 MiB and 2,048 capabilities.
- Share plugin identity and installed-version selection in `codex-core-plugin-common`, and fall back to `.app.json` when a plugin does not declare an apps configuration.
The V2 discovery manager is not yet wired into RPC request dispatch.
## Testing
Add coverage for inventory metadata, sandbox cache isolation, watcher invalidation, startup scan failures, response limits, and compatibility with older executor metadata.
GitOrigin-RevId: a223a5bc15fdf251023c0c71f468fd92c3b2d847
Anthony Tafoya