More granular table traits

[onx2]

Description of Changes

This looks like a large diff but the real changes are just sdks/rust/src/lib.rs for traits and crates/codegen/src/rust.rs for the new codegen.

Refactored the Rust SDK table trait surface into composable capabilities and updated Rust codegen to match. Discord thread

Summary

• Added a shared TableLike trait for common table handle functionality:
  • Row
  • EventContext
  • count
  • iter
• Added capability traits:
  • WithInsert
  • WithDelete
  • WithUpdate
• Changed umbrella traits to compose those capabilities:
  • Table: TableLike + WithInsert + WithDelete
  • TableWithPrimaryKey: Table + WithUpdate
  • EventTable: TableLike + WithInsert
• Updated Rust binding codegen to emit separate impl blocks for:
  • TableLike
  • WithInsert
  • WithDelete
  • WithUpdate
  • plus empty umbrella impls for Table, TableWithPrimaryKey, and EventTable
• Updated generated-doc references for callback APIs
• Exported the new traits through both the Rust SDK public API and spacetimedb_sdk::__codegen so generated bindings can compile correctly

API and ABI breaking changes

Yes — this is an API-breaking change in the Rust SDK trait hierarchy.

Notable changes:

• insert callbacks are now provided via WithInsert
• delete callbacks are now provided via WithDelete
• update callbacks are now provided via WithUpdate
• generated Rust bindings now implement multiple capability traits instead of placing all methods in a single Table / EventTable impl block

Expected complexity level and risk

3/5

This is a moderate refactor because it changes the Rust SDK trait model, affects Rust code generation, and requires the generated binding surface and SDK re-export surface to stay in sync.

Main interaction points:

• sdks/rust/src/table.rs
• sdks/rust/src/lib.rs
• crates/codegen/src/rust.rs

Testing

• Ran cargo check --manifest-path /Users/onx2/Documents/projects/SpacetimeDB/sdks/rust/Cargo.toml
• Ran cargo test --manifest-path /Users/onx2/Documents/projects/SpacetimeDB/Cargo.toml -p spacetimedb-codegen test_codegen_rust
• Regenerated Rust client bindings using the workspace CLI and verified generated impls match the new trait structure
• Reviewer: regenerate a Rust client with the workspace CLI and confirm the generated bindings compile cleanly

[onx2]

This is the main change to functionality. I wanted to have access to specific traits so in bevy_stdb I can go from:

Before/after

fn bind_insert<TRow, TTable>(world: &World, table: &TTable)
where
    TRow: Send + Sync + Clone + InModule + 'static,
    RowEvent<TRow>: Send + Sync,
-   TTable: Table<
+   TTable: WithInsert<
            Row = TRow,
            EventContext = <<TRow as InModule>::Module as SpacetimeModule>::EventContext,
        >,
    TTable::EventContext: AbstractEventContext<Event = RowEvent<TRow>>,
{
    let sender = channel_sender::<InsertMessage<TRow>>(world);
    table.on_insert(move |ctx, row| {
        let _ = sender.send(InsertMessage {
            event: ctx.event().clone(),
            row: row.clone(),
        });
    });
}

[onx2]

Trait changes mean we need updated codegen too (breaking).

[onx2]

Do we need these empty impls? Maybe now Table can just be removed entirely?