refactor: define system-wide Event types and use in homeserver and SDK

[86667]

This should have been like this from initial impl: Api consumer types in pubky-common module.

changes in SDK are due to:

1. Wasm not liking Rust enums
2. base64 decoding into Hash object instead of using String

[Copilot]

Pull request overview

This PR refactors the event streaming system to consolidate event types (EventType and EventCursor) from individual implementations in the homeserver and SDK into a shared pubky-common module. The refactoring also improves type safety by replacing string-based content hashes with proper Hash objects and base64 encoding for transport.

Changes:

• Created new pubky-common/src/events.rs module defining EventType (enum with Put { content_hash: Hash } and Delete variants) and EventCursor types
• Updated SDK and homeserver to use the shared types from pubky-common::events
• Modified WASM bindings to wrap the Rust enum in a struct-based API that works with JavaScript
• Updated all tests and examples to use the new API

Reviewed changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pubky-common/src/events.rs	New shared module defining EventType enum and EventCursor struct with comprehensive tests
pubky-common/src/lib.rs	Export the new events module
pubky-sdk/src/actors/event_stream.rs	Refactored to use pubky_common::events types, added base64 decoding for content hashes from SSE, removed duplicate type definitions
pubky-sdk/bindings/js/src/wrappers/event_stream.rs	WASM-compatible wrappers for EventType and EventCursor, converting Rust enums to struct-based API with helper methods
pubky-sdk/bindings/js/pkg/tests/events.ts	Updated TypeScript tests to use new API methods (isPut(), isDelete(), contentHash())
pubky-sdk/bindings/js/Cargo.toml	Added base64 dependency for WASM bindings
pubky-homeserver/src/persistence/files/events/*.rs	Updated to import and use types from pubky_common::events instead of local definitions
pubky-homeserver/src/persistence/files/events/events_entity.rs	Fixed duplicate variable declaration bug, uses shared EventType and EventCursor
examples/rust/7-events_stream/main.rs	Updated to use new EventType.content_hash() API instead of direct field access
Cargo.lock	Added base64 dependency for WASM package

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[dzdidi]

Some nits. But I would wait for SDK review from @SHAcollision

[SHAcollision]

Overall LGTM. I just left a few minor questions.

[SHAcollision]

eventType and cursor changed from string fields to object wrappers, just wondering if this is intentional and we confirmed this results on an ergonomic improvement rather than a hassle for JS devs.

[86667]

This is part of the SDK using the types defined in pubky-common to brings consistency across codebases.

[SHAcollision]

It doesn't answer the question of whether JS consumer should see the complex types or not. I guess it's okay?

[86667]

Thanks for calling that out. Ive taken another look and agree that i was thinking too Rusty for JS. Ive removed these more complex types going back to string for cursor and eventType