fix: support multiple foundational stores

[driescroons]

Problem

Modules can declare multiple foundational-store inputs, and the WASM runtimes assign each input its own index. The server only wired clients from the first input, so accessing index 1 failed with invalid foundational store index 1, 1 stores declared.

Fix

Wire exactly one client for each foundational-store input in declaration order. Reject unsupported client cardinality before execution instead of silently corrupting guest indexes.

Verification

• go test ./pipeline/...
• go vet ./pipeline/...
• go build ./...
• focused host index-routing tests
• release-note validation
• git diff --check

[maoueh]

Hey, was this an agentic mistake or something else?

Happy to update skills/docs if it was, to
avoid this for someone else.

Unless it's something else …?