fix(postgrest): stop duplicating the package id in X-Client-Info

[grdsdev]

Problem

Helpers.PrepareRequestHeaders prefixed the shared header helper with a literal postgrest-csharp/:

headers.Add("X-Client-Info", $"postgrest-csharp/{Util.GetAssemblyVersion(typeof(Client))}");

Util.GetAssemblyVersion (Core/Util.cs:33) already returns {assemblyname-lowercased}-csharp/{version}{metadata}. The emitted header was therefore:

postgrest-csharp/supabase.postgrest-csharp/8.0.0

The package id appears twice, and the value has three /-delimited segments instead of two. Any consumer that splits on / reads the version slot as supabase.postgrest-csharp.

Scope

Postgrest was the only outlier. The other five call sites pass the helper through unmodified and are correct:

• Storage/StorageBucketApi.cs:39
• Gotrue/Api.cs:43
• Functions/Client.cs:180
• Realtime/RealtimeSocket.cs:84
• Supabase/Client.cs:296, Supabase/StatelessClient.cs:167

So the fix belongs in Postgrest, not in Util.

Change

• Drop the redundant prefix; pass Util.GetAssemblyVersion(typeof(Client)) through as-is.
• Fallback path (used when the version can't be resolved, e.g. Unity Editor / IL2CPP) keeps a package identifier but no longer duplicates it: supabase.postgrest-csharp/session-{AppSession}.
• RequestHeaderTests.cs:62 asserted StartWith("postgrest-csharp/"). That passed only because of the bug — the assembly name is Supabase.Postgrest, so the corrected header starts with supabase.postgrest-csharp/. Updated to match, which mirrors Functions.Tests/ClientContractTests.cs:116 (supabase.functions-csharp/).

Impact

Confirmed against production telemetry (supabase-etl-prod-eu.dbt.supabase_client_lib_requests): this is the largest C# request bucket, roughly 648M requests/30d on v4 plus 31k on v8.

Open item: downstream telemetry parsing

The header shape changes for every Postgrest request once this ships, so the dbt mart likely needs a compensating change:

• New rows emit two segments: supabase.postgrest-csharp/8.x.x.
• Historical rows (the ~648M/30d bucket) emit three: postgrest-csharp/supabase.postgrest-csharp/4.x.x.

If the mart splits on / and takes index 1 as the version, it will keep mis-parsing history and start parsing new rows correctly — so a period of mixed shapes needs handling either way. A parser that takes the last /-delimited segment as the version, or that strips a leading postgrest-csharp/ when a second -csharp/ segment follows, handles both.

I could not verify the actual model: the only accessible dbt repo (supabase/dbt) is private and archived since 2023, and does not contain a supabase_client_lib_requests model. Someone with access to the live mart should confirm before this is released.

Testing

Not run locally — no .NET SDK on this machine. CI covers Postgrest.Tests.