Add pluggable activity context

[heyitsaamir]

This PR introduces the ability for plugins to add typed values to the activity context. It does this by adding a dedicated buildActivityContext function that gets called in app.process. Then via a bunch of generics plumbing we merge the plugin's context values with the default ones.

We can use this to separate graph out into other packages, but keep the contextual objects for the activity-handlers unchanged (aka. appGraph, and userGraph will still be available). However, graph object on app would most likely be part of the the GraphPlugin - (maybe we make that accessible via a new app.getPlugin('graph') method?)

Here's a mini demo:

Screen.Recording.2025-08-04.at.8.35.09.AM.mov

PR Dependency Tree

• PR Add pluggable activity context #288 👈

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[Copilot]

Pull Request Overview

This PR introduces a pluggable activity context system that allows plugins to add typed values to the activity context. The implementation adds a new buildActivityContext method to the plugin interface and updates all activity context types to support generics for plugin-provided context values.

Key changes:

• Adds buildActivityContext method to the plugin interface for injecting typed context values
• Updates all activity context interfaces and route types to accept generic context parameters
• Implements context merging logic in the app processing pipeline

Reviewed Changes

Copilot reviewed 20 out of 20 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/apps/src/types/plugin/plugin.ts	Adds generic type parameters and buildActivityContext method to plugin interface
packages/apps/src/contexts/activity.ts	Updates activity context interfaces to support generic plugin context types
packages/apps/src/app.process.ts	Implements plugin context building and merging in activity processing
packages/apps/src/routes/*.ts	Updates all route type definitions to support generic context parameters
packages/apps/src/router.ts	Updates router class to support typed plugin contexts
packages/apps/src/app.ts	Updates app class to use typed plugin contexts in router
packages/apps/src/types/app-routing.ts	Adds utility type for extracting plugin context types

[aacebo]

left questions, this is a good first draft let me know when its ready for another review!

[heyitsaamir]

left questions, this is a good first draft let me know when its ready for another review!

Updated it with your suggestions @aacebo . Take a look!