Tyler Cloutier 57b7ef5e79 Limit update() to only work on primary keys (#4279) ...

## Summary
- Restricts `update()` across all three server-side SDKs (Rust, C#,
TypeScript) to only work on primary key columns, not all unique columns
- Calling `update()` on a non-PK unique column is semantically a
delete+insert — clients won't see it as a row update unless the primary
key stays the same
- Fresh re-implementation of #1862, extended to cover C# and TypeScript
bindings

### Design principle

Primary key is a constraint on columns, not a property of indexes. An
index is unique or not unique — whether `update()` is available is
derived from the column's attributes at the point of use, not stored on
the index.

This differs from #1862 which introduced a `Uniqueness` enum (`No |
Unique | PrimaryKey`) on the index itself. Instead, we keep `is_unique:
bool` and check the column metadata where needed.

### Rust changes
- Add `PrimaryKey` marker trait and `where Col: PrimaryKey` bound on
`UniqueColumn::update()`
- `marker_type()` receives `primary_key_column` and checks the column
directly — no `is_pk` field on the index
- `sdk-test` unique tables use `update_non_pk_by` (delete+insert)
instead of `update_by`
- Benchmarks that used `update()` on `#[unique]` columns changed to
either `#[primary_key]` or delete+insert

### C# changes
- Only emit `Update()` on `UniqueIndex` when the column has `PrimaryKey`
attrs
- Update `unique_*` test reducers in `sdk-test-cs` to use
`Delete()`+`Insert()` instead

### TypeScript changes
- `UniqueIndex` now has only `find` + `delete` (no `update`)
- `AllColumnsPrimaryKey` type-level helper checks column metadata from
the `TableDef`
- `Index` routing conditionally intersects `{ update() }` when columns
are PK
- Runtime only attaches `update` method for PK unique indexes
- `sdk-test-ts` unique tables use delete+insert instead of update
- Type-level test in `schema.test-d.ts` verifies `id.update()` compiles
(PK) and `name2.update` errors (non-PK unique)

## Test plan
- [x] C# codegen tests pass (`dotnet test
crates/bindings-csharp/Codegen.Tests`)
- [x] Rust SDK test module compiles
- [x] Benchmarks compile
- [x] TypeScript type checks pass (`npx tsc --noEmit`)
- [ ] CI passes

Closes #1862

2026-02-13 00:56:54 +00:00

..

circles.rs

Add modules/benchmarks-ts (#3408)

2025-10-24 16:34:13 +00:00

ia_loop.rs

Limit update() to only work on primary keys (#4279)

2026-02-13 00:56:54 +00:00

lib.rs

Add small 'realistic' workload benchmark integration test (#714)

2024-06-13 18:28:35 +00:00

synthetic.rs

Limit update() to only work on primary keys (#4279)

2026-02-13 00:56:54 +00:00