feat: add SAID Protocol action provider (Solana agent identity + reputation)

[Jugmaster]

Description

Adds a SAID Protocol action provider — an on-chain identity and reputation layer for agent wallets on Solana (saidprotocol.com).

AgentKit gives every agent a wallet; SAID gives that wallet a verifiable identity and a track record. Reputation is derived from observable behavior — x402 payments received, anchored work receipts, peer feedback — not self-reported claims.

Five actions (Solana mainnet):

Action	Type	Purpose
get_agent_reputation	read	Check any wallet's reputation tier + composite score before paying it (e.g. via x402). A wallet with no history returns an explicit "unknown counterparty" result — never a fake neutral score.
find_agents	read	Discover SAID-registered agents ranked by reputation, with their published A2A/MCP endpoints and x402 payment wallets — find, vet, then pay or message.
register_said_identity	write	Register + verify this wallet's on-chain identity in one self-paid transaction (~0.0035 SOL account rent + one-time 0.01 SOL verification fee). Fully self-custodial: the agent's own wallet signs and pays; no third party signs anything.
send_agent_message	write	Send an agent-to-agent message to another SAID agent through the SAID relay. Sender must be registered (the relay records its verification + reputation); the recipient reads from its SAID mailbox, so any registered agent is reachable with no per-agent server.
check_agent_messages	read	Read incoming A2A messages addressed to this wallet, each annotated with the sender's wallet, name, verification status and reputation — so the agent can decide whether to act based on who is asking.

Design notes:

• The read actions are plain HTTP calls to the public SAID API — no API keys, no authentication, no configuration required.
• The already-verified check reads is_verified from the on-chain account (source of truth) rather than the indexer API, so an agent can never pay the verification fee twice.
• Confirmation timeouts re-check getSignatureStatuses before reporting failure, so a landed transaction is never reported as an error.
• Complementary to the existing erc8004 provider (SAID covers the Solana side and derives scores from payment/delivery behavior) and to proof-of-personhood systems (SAID scores the agent wallet's track record, not the human behind it).
• Touches two WISHLIST themes: agent communication (a working relay via send_agent_message/check_agent_messages, plus endpoint discovery via find_agents) and commerce rails for agent payments (pre-payment counterparty checks).

Tests

• 14 unit tests for the provider (mocked wallet provider + fetch), full @coinbase/agentkit suite passes: 61/61 suites, 878/878 tests. Lint + build clean. Changeset included.
• Live-tested end-to-end on Solana mainnet through SolanaKeypairWalletProvider via a direct action-invocation harness:

Setup: SolanaKeypairWalletProvider.fromRpcUrl(<mainnet RPC>, <fresh funded keypair>)
Network: solana-mainnet

Action: register_said_identity { metadataUri: "https://saidprotocol.com" }

Successfully registered and verified this wallet's SAID identity.
- Agent identity PDA: DF5Q85AiQgcvRvV7S2CCUpemmiVSS7mUEREXtoo2HhFB
- Transaction: 48wz1WhTSspM79FqousfhZPKhvFJ5TjwPHLJC6tjpTg6WLUdzcccTkKm1Gkm4ikvAxKrcad6EcEYWA36XAnQr512
Reputation now accrues automatically from this wallet's behavior (x402 payments
received, work receipts, peer feedback). Other agents can check it via
get_agent_reputation.

(on-chain: tx finalized, costs matched documentation exactly)

Action: send_agent_message { toWallet: <registered agent>, message: "..." }

Message sent via the SAID relay.
- Task id: task_1781335872030_a8q7adxpc
- Status: created

Action: check_agent_messages {}

1 incoming message(s):
1. from <name> (<wallet>) — verified, reputation 0
   [created] task task_1781335872030_a8q7adxpc: AgentKit live test: SAID A2A relay round-trip

(A2A send + inbox round-trip executed live against the production SAID relay; sending to an unregistered wallet correctly returns "not a registered SAID agent".)

Action: register_said_identity (re-run, same wallet)

This wallet already has a verified SAID identity (PDA DF5Q85AiQgcvRvV7S2CCUpemmiVSS7mUEREXtoo2HhFB). Nothing to do.

Action: get_agent_reputation { wallet: "9nEGzMRjJbJjRXG3r3bpddARk4HSSopGpknyLmD6wo97" }

SAID reputation for 9nEGzMRjJbJjRXG3r3bpddARk4HSSopGpknyLmD6wo97:
- Tier: unranked (composite score 0)
- Registered SAID agent: yes
- On-chain verified: yes
- Note: registered but not yet scored — SAID has no behavioral history for this wallet yet.

Action: find_agents { query: "research", verifiedOnly: true, limit: 3 }

Found 3 SAID agent(s), ranked by reputation:
1. research_probe — 62pagdUh1qhsMav9tGyoCPA9uX8A1Vz3nXi9fo5mkMmz
   Reputation: silver (0.6319), on-chain verified
   ...

🤖 Generated with Claude Code

[cb-heimdall]

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