refactor: consolidate agent/editor plugins under integrations/ (#5491)

Co-authored-by: Claude <noreply@anthropic.com>

integrations/pi-agent-plugin/src/prompt.ts

@@ -0,0 +1,16 @@
+export const MEMORY_POLICY = `<mem0-memory-policy>
+You have persistent semantic memory via the mem0_memory tool, powered by Mem0.
+
+Memory is scoped to the current project by default. Do not change the scope unless explicitly asked.
+- "project" (default): memories for this project — use this for all normal queries
+- "session": memories from this session only
+- "global": all memories across projects — ONLY use when the user explicitly asks for cross-project search
+
+When to use memory:
+- Search when the user references past conversations, preferences, or decisions
+- Save important facts, user preferences, key decisions, and lessons learned
+- Check memory before asking the user something they may have already told you
+- Save identity information, goals, relationships, and routines the user shares
+
+Memory persists across sessions and devices via Mem0's cloud.
+</mem0-memory-policy>`;