Migration: subxt::dynamic → typed storage_subxt bindings

Follow-up https://github.com/paritytech/web3-storage/pull/207#discussion_r3465733093

The storage-subxt crate (storage-subxt/) contains pre-generated, fully-typed Rust bindings for the parachain runtime, produced by subxt-cli from metadata/storage_paseo_runtime.scale. These bindings provide:

• Typed transactions via runtime::tx().storage_provider().*(), runtime::tx().drive_registry().*(), etc.
• Typed storage queries via runtime::storage().storage_provider().*(), etc.
• Typed runtime API calls via runtime::apis().storage_provider_api().*().
• Generated runtime types under runtime_types::* — the canonical source of truth for all on-chain structs (e.g. pallet_storage_provider::pallet::ProviderInfo, ProviderSettings, ProviderStats, BoundedVec).

Before this work, several parts of the codebase used subxt::dynamic::tx(...) and subxt::dynamic::storage(...) with manually constructed ScaleValue trees, and declared local hand-rolled structs that duplicated fields already present in the generated types.

TODO:

Rust clients: client/*, storage-interfaces/s3/client/src/substrate.rs, storage-interfaces/file-system/client/src/substrate.rs
Use storage-subxt as trusted type definition

• Eliminate subxt::dynamic calls
• Replace hand-rolled types with generated equivalents
• Replace sp-runtime with subxt_core , storage_subxt

Note: The HTTP /info response from provider-node changed shape as a side effect of this migration. Any external HTTP client consuming /info must be updated.