fix(skills): update local-node-validation with 5 infrastructure findings

[Keinberger]

Context

Builders testing contracts against real local nodes hit several undocumented behaviors.

Changes

Updates to .claude/skills/local-node-validation/SKILL.md:

• add_account() only stores the account in the local client store (IndexedDB for web, SQLite for Rust). To deploy on-chain, submit a transaction involving the account.
• gRPC service paths are /rpc.Api/SyncState, /rpc.Api/GetAccount, etc. Not /miden*. Vite proxy must match /rpc.Api/ prefix.
• Delete store.sqlite3 when switching between local node and testnet. The store caches the genesis hash and fails with "accept header validation failed" on network mismatch.
• Node/client version pairing: cargo install miden-node may give an older version incompatible with the current client. Keep guidance generic. Instruct agents to verify version compatibility and use --git --tag when needed.
• NoteTag subscription model: notes with Tag(0) are not served during sync because no routing bits are set. Clients must explicitly subscribe to relevant tags. Notes still exist and are queryable if the client subscribes. Works in MockChain (bypasses sync).