fix: allow contract view calls without execute

[Urazanev]

Summary

• Execute view/pure contract calls through the read path even when --execute is not provided
• Keep mutating contract writes in preview mode until explicit --execute
• Fix the upvoting skill examples to use the published agw-cli command name

Why

The upvoting skill documents read-only contract calls such as voteCost(), currentEpoch(), and userVotesRemaining(address) using contract write --dry-run. Before this change those calls returned only a preview envelope, so the user could not get the actual return value needed before voting. Since view/pure calls cannot mutate state, they can safely be executed via readContract without requiring explicit execute intent.

Test plan

• corepack pnpm jest test/agw-runtime.test.ts --runInBand
• corepack pnpm jest --runInBand
• corepack pnpm lint
• ./node_modules/.bin/tsc -p tsconfig.json --noEmit
• corepack pnpm --dir packages/agw-core check-types
• corepack pnpm --dir packages/agw-cli check-types
• corepack pnpm --dir app check-types