personas: elevate to server with per-persona fact scoping

Move personas off the mobile client into ImageApi as first-class
records, and scope entity_facts by persona so each one builds its own
voice over a shared entity graph. The new include_all_memories flag
lets a persona opt back into the full hive-mind pool for human
browsing of /knowledge/*; agentic generation always stays in-voice.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib.rs

@@ -26,6 +26,7 @@ pub mod memories;
 pub mod otel;
 pub mod parsers;
 pub mod perceptual_hash;
+pub mod personas;
 pub mod service;
 pub mod state;
 pub mod tags;