[codex] Centralize Plugin Analytics Metadata

[jameswt-oai]

This PR moves construction of PluginTelemetryMetadata from loader and model helpers into PluginsManager, which already owns installed plugin state and will eventually perform remote identity enrichment. The metadata type remains in codex-plugin, and serialized analytics events remain unchanged.

Before

flowchart LR
    subgraph Events["Analytics event paths"]
        direction TB
        Lifecycle["Local install / uninstall"]
        Config["Enable / disable"]
        Remote["Remote install"]
        Used["Plugin used"]
    end

    subgraph Construction["Metadata construction"]
        direction TB
        Loader["Loader telemetry helpers"]
        Summary["PluginCapabilitySummary::telemetry_metadata"]
        Override["Caller adds remote_plugin_id"]
    end

    Metadata["PluginTelemetryMetadata"]

    Lifecycle --> Loader
    Config --> Loader
    Remote --> Loader
    Loader -->|"local events"| Metadata
    Loader -->|"remote install"| Override
    Override --> Metadata
    Used --> Summary
    Summary --> Metadata

Loading

Telemetry metadata was constructed through loader helpers, a capability-summary method, and a remote-install call-site override.

After

flowchart LR
    subgraph Events["Analytics event paths"]
        direction TB
        Lifecycle["Local install / uninstall"]
        Config["Enable / disable"]
        Remote["Remote install"]
        Used["Plugin used"]
    end

    Manager["PluginsManager — single construction owner"]
    Metadata["PluginTelemetryMetadata"]

    Lifecycle --> Manager
    Config --> Manager
    Remote -->|"authoritative remote ID"| Manager
    Used -->|"capability summary"| Manager
    Manager --> Metadata

Loading

Every analytics path delegates metadata construction to PluginsManager. Remote install still supplies its authoritative backend ID explicitly.

What Changes

• Make loader code return a focused plugin capability summary instead of constructing analytics metadata.
• Centralize immutable plugin telemetry metadata construction in PluginsManager.
• Route local install/uninstall, remote install, enable/disable, and plugin-used emitters through the manager.
• Preserve the current serialized analytics contract exactly.

Normal metadata still has no remote override. Remote install continues to provide its authoritative backend ID explicitly, so the existing serializer continues reporting that ID through plugin_id. Snapshot-based enrichment is intentionally deferred to the final PR.

Testing

• just test -p codex-core-plugins (238 tests passed)
• just test -p codex-plugin (3 tests passed)
• Scoped Clippy/compile checks passed for codex-plugin, codex-core-plugins, codex-app-server, and codex-core.

Split Overview

main
├── #27093  Debug analytics capture                 (merged)
├── #27099  Non-mutating plugin smoke               (merged)
├── #27100  Remote install/uninstall smoke          (merged)
└── #27102  Plugin telemetry metadata refactor      ← you are here
    └── #27669  Persist remote plugin identity

After #27102 and #27669 merge:
└── Final PR: add explicit local and remote IDs to plugin analytics

Review order and dependencies:

1. #27093 Add debug-only analytics event capture (merged)
2. #27099 Add a plugin analytics smoke workflow (merged)
3. #27100 Add a remote plugin analytics mutation smoke workflow (merged)
4. This metadata refactor, independent and based on main
5. #27669 Persist remote plugin identity, stacked on this PR
6. Final remote-ID behavior PR, created after the prerequisites merge

The original #26281 remains open as the aggregate reference until the final replacement PR is published.