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/database/schema.rs

@@ -57,6 +57,7 @@ diesel::table! {
         confidence -> Float,
         status -> Text,
         created_at -> BigInt,
+        persona_id -> Text,
     }
 }
 
@@ -159,6 +160,20 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    personas (id) {
+        id -> Integer,
+        user_id -> Integer,
+        persona_id -> Text,
+        name -> Text,
+        system_prompt -> Text,
+        is_built_in -> Bool,
+        include_all_memories -> Bool,
+        created_at -> BigInt,
+        updated_at -> BigInt,
+    }
+}
+
 diesel::table! {
     persons (id) {
         id -> Integer,
@@ -249,6 +264,7 @@ diesel::joinable!(entity_photo_links -> libraries (library_id));
 diesel::joinable!(face_detections -> libraries (library_id));
 diesel::joinable!(face_detections -> persons (person_id));
 diesel::joinable!(image_exif -> libraries (library_id));
+diesel::joinable!(personas -> users (user_id));
 diesel::joinable!(persons -> entities (entity_id));
 diesel::joinable!(photo_insights -> libraries (library_id));
 diesel::joinable!(tagged_photo -> tags (tag_id));
@@ -265,6 +281,7 @@ diesel::allow_tables_to_appear_in_same_query!(
     image_exif,
     libraries,
     location_history,
+    personas,
     persons,
     photo_insights,
     search_history,