Improve subgraph query support and URL construction

[luchobonatti]

Objective

Improve the subgraph integration in dAppBooster to support flexible URL construction, shared queries across subgraphs, schema-driven query authoring, and better documentation for parameterized queries.

Rationale

The current subgraph setup has friction points that force repetitive work (duplicating queries per subgraph), require manual URL assembly with three separate env vars, and lack schema support for query authoring. Addressing these reduces boilerplate, prevents errors, and lowers the barrier for new contributors working with subgraphs.

Scope

In scope:

• Development URL construction with user-id, subgraph-slug, and subgraph-version parameters (expected format: https://api.studio.thegraph.com/query/[user-id]/[subgraph-slug]/version/[subgraph-version])
• Mechanism to define a query once and run it against multiple subgraphs without duplicating it into each subgraph folder
• Schema-first workflow so queries can be written against a pre-generated schema
• Documentation section covering parameterized queries

Out of scope:

• Production/decentralized network URL changes
• Migration to alternative subgraph providers

Architecture & technical considerations

No response

Dependencies

No response

Issue breakdown

• Fix development URL construction to accept user-id, subgraph-slug, and subgraph-version
• Support shared queries across multiple subgraphs without per-folder duplication
• Add schema generation/download step so queries can be authored against a known schema
• Document how to pass parameters to subgraph queries

Acceptance criteria

• Development subgraph URLs are correctly constructed from three parameters
• A single query definition can target multiple subgraphs
• A schema file is available before query authoring
• Documentation covers parameterized query usage with examples

Owner / DRI

No response

Target milestone

No response