docs(landing): correct service map edges and stale claims on the OTel conventions page - #1066

Confidence 3/5 · needs attention
_{quality 100/100 · no findings · tests not needed · risk low}

Repoints the two remaining @effect-agent/core/AgentError imports in the PR-review failure path to effect-agent/agent-error, completing the beta.142 package migration, and rewrites the OTel conventions page. The code change is a pure specifier swap and is safe to merge.

• review-failure.ts and its test import agent errors from effect-agent/agent-error

_{119772b · Updated on every push. Reply "won't fix" to dismiss a finding, or mention @maple to ask about one.}