Fix OpenCode planning agent resolution for display names

[pysol-dev]

Summary

• Resolve configured OpenCode planningAgents to existing agent config keys before mutating permissions.
• Match display-name agent keys such as Prometheus - Plan Builder / Sisyphus (Ultraworker) and keys prefixed with zero-width characters, avoiding duplicate raw prometheus / sisyphus agent entries.
• Preserve allow permissions during the later non-planning-agent deny pass by tracking resolved planning-agent config keys.

Verification

• bun test apps/opencode-plugin/workflow.test.ts ✅
• LSP diagnostics clean for apps/opencode-plugin/workflow.ts and apps/opencode-plugin/workflow.test.ts ✅
• bun test apps/opencode-plugin was attempted, but this temp checkout lacks workspace dependency resolution for @plannotator/server, so unrelated command tests fail before exercising this change.

Context

This fixes a real OpenCode config interaction where planningAgents: ["prometheus", "sisyphus"] created extra raw agent entries instead of reusing existing OhMyOpenCode display-keyed agent configs.