fix(eve-extension): rebuild against eve 0.68.0, raise peer floor to >=0.68.0

[upstash-tag]

Bumps @upstash/agentkit-eve-extension's eve devDependency to ^0.68.0 (and examples/eve-extension-demo alongside it) and raises its peerDependencies.eve floor from >=0.65.0 to >=0.68.0, because the extension rebuilt against 0.68.0 stamps contract numbers (tool 59 / dynamicTool 56 / hook 29) that no eve release before 0.68.0 supports — left at the old floor, a consumer on eve 0.65–0.67 would install cleanly and only fail later at eve build. Updates the extension's README/AGENTS.md version lines and CLAUDE.md's compatibility notes to match, and adds a changeset (no existing unreleased one covered this bump).

packages/eve is deliberately left untouched on eve ^0.65.0: rebuilding it against 0.68.0 breaks its build/typecheck because src/sandbox.ts imports MutableNetworkSandboxSession from eve/sandbox, a type eve removed in 0.66.0. That's a real source-level port, not a mechanical bump, so it isn't done here — CLAUDE.md now records why the two packages are on different eve versions, and the existing follow-up task for the sandbox.ts port stands.

Verified: packages/eve-extension build/typecheck/unit tests pass on eve 0.68.0; whole-repo pnpm -r build/typecheck/lint pass; examples/eve-extension-demo, examples/eve-demo and examples/ai-sdk-demo all build. The mocked-model eval in eve-extension-demo ran and its extension tools fired correctly, but every attempt (4 runs, 2 fresh throwaway Redis databases) died mid-run because the throwaway Redis instance stops answering ~25s after creation regardless of load (confirmed with an untouched control database) — inconclusive infrastructure flakiness, not caused by this change, and worth re-checking against CI's real Redis before merge.

---

Built by upstash-tag · mission 006f7bc3-516a-4b8e-b3e2-ce897e7cea36 · eve/extension-0.68-peer-floor → main · $8.68