Add Validate proxy support to runtime and Python SDK

[cisterciansis]

Summary

• add ProxyType::Validate with stable on-chain ID 18
• restrict Validate proxies to validator operations: weight set/commit/reveal calls, axon serving, EVM association, and commitments
• preserve existing subnet set_weights call sites by reading the exact target hotkeys from WEIGHT_TARGETS
• support any ordering and mixture of the signing hotkey and proxied hotkeys, including an empty set that performs no submission
• isolate each target with Utility.force_batch, so a stale, revoked, or otherwise failing proxy cannot interrupt valid targets
• return an ordered per-target outcome in result.data["weight_results"]

Attribution

This work carries forward the original ProxyType::Validate runtime design and test groundwork from #2543, authored by @ppolewicz. Thank you to Paweł Polewicz for proposing and implementing the original scoped validator proxy.

This PR adapts that work to the current monorepo proxy-filter metadata model and adds the previously missing Python SDK integration.

Why

A validator operator may be authorized by several hotkeys to compute one weight vector and submit it for each validator. The runtime needs a narrow proxy role that cannot transfer value or manage stake. For commit-reveal subnets, the SDK must also preflight and timelock-encrypt against each real validator hotkey rather than the delegate key.

Unlike #2543, Validate proxies in this version cannot create additional proxies; each validator owner grants the delegate directly.

SDK behavior

Existing subnet weight-setting code does not change:

WEIGHT_TARGETS=5F...DELEGATE,5F...VALIDATOR_A,5F...VALIDATOR_B

await client.execute(
    bt.SetWeights(netuid=1, weights={0: 0.2, 1: 0.8}),
    delegate_wallet,
)

Configuration semantics:

• unset WEIGHT_TARGETS: preserve existing single-wallet behavior
• empty WEIGHT_TARGETS: successful no-op without signing or submission
• comma-separated targets: the supplied wallet hotkey is direct; every other target is dispatched through a zero-delay Validate proxy
• explicit constructor weight_targets= remains available and overrides the environment

Each target is built against its real validator identity, including commit-reveal registration, rate-limit, and timelock-encryption inputs. Target-specific SDK preflight failures are recorded without blocking other targets.

The SDK deliberately does not preverify the complete proxy configuration before submission. Each Proxy.proxy call is authoritative on-chain, and Utility.force_batch continues after an invalid or revoked grant. This prevents one bad target from blocking a larger validator operation. The result preserves configured order:

result.data["weight_results"]
# [{"target": "5F...", "success": True}, ...]

A single extrinsic has one signer, so the supplied wallet is the only direct signer in one execution. Other configured addresses are proxied targets.

Fees and weight refunds

set_mechanism_weights is Pays::No. Proxy.proxy inherits the inner call fee classification, and Utility keeps a batch fee-free when every child is fee-free. Runtime tests assert that direct, proxied, and force_batch weight calls all remain Pays::No.

force_batch also returns accumulated actual child weight. A Utility regression test verifies that successful children refund declared weight minus actual weight across the batch.

Regression coverage

The existing live clone proxy-filter regression now creates a Validate relationship and exercises:

• mechanism weight submission
• axon serving
• TLS axon serving
• EVM-key association
• commitments
• rejection of a balance transfer

It intentionally does not exercise drand. The live clone test was typechecked locally; execution requires a clone/localnet endpoint and runs in the repository clone regression job.

Validation

• full Python SDK suite: 1,073 passed, 1 skipped
• focused intent/executor suite: 504 passed
• Ruff lint and format: passed
• TypeScript clone regression typecheck: passed
• SKIP_WASM_BUILD=1 cargo test -p node-subtensor-runtime proxy_filters --lib: 14 passed
• SKIP_WASM_BUILD=1 cargo test -p node-subtensor-runtime transaction_payment_wrapper::tests --lib: 26 passed
• Utility successful-weight-refund regression: passed
• cargo fmt --check: passed

Local environment note

The native WASM build could not run locally because Apple clang lacks a wasm32 backend for the zstd C build.

[vercel]

@cisterciansis is attempting to deploy a commit to the RaoFoundation Team on Vercel.

A member of the Team first needs to authorize it.