chore: finalize redb migration for all memory stores

server/src/state.rs

@@ -1,6 +1,6 @@
 use crate::models::*;
 use crate::search::MemoryIndex;
-use crate::store::{Store, read_json_file, write_json_atomic};
+use crate::store::Store;
 use std::collections::{HashMap, HashSet};
 use std::fs;
 use std::path::PathBuf;
@@ -76,7 +76,21 @@ impl MemoryState {
         let mut lock = self.master_cache.write().unwrap();
         let new_mtime = self.master_mtime();
         if lock.1 != new_mtime {
-            lock.0 = read_json_file(&self.master_path);
+            if let Ok(data) = fs::read(&self.master_path)
+                && let Ok(parsed) = serde_json::from_slice(&data)
+            {
+                lock.0 = parsed;
+            } else {
+                let bak_path = self.master_path.with_extension("json.bak");
+                if let Ok(data) = fs::read(&bak_path)
+                    && let Ok(parsed) = serde_json::from_slice(&data)
+                {
+                    let _ = fs::write(&self.master_path, data);
+                    lock.0 = parsed;
+                } else {
+                    lock.0 = KnowledgeGraph::default();
+                }
+            }
             lock.1 = new_mtime;
         }
         lock.0.clone()
@@ -133,7 +147,18 @@ impl MemoryState {
         let _ = fs::remove_file(&wal_path);
         *self.session_graph.write().unwrap() = KnowledgeGraph::default();
         update_fn(&mut master);
-        let _ = write_json_atomic(&self.master_path, &master);
+        
+        let write_json = |path: &std::path::Path, data: &KnowledgeGraph| -> std::io::Result<()> {
+            if path.exists() {
+                let bak_path = path.with_extension("json.bak");
+                let _ = fs::copy(path, &bak_path);
+            }
+            let tmp_path = path.with_extension("json.tmp");
+            let json_data = serde_json::to_string_pretty(data)?;
+            fs::write(&tmp_path, json_data)?;
+            fs::rename(&tmp_path, path)
+        };
+        let _ = write_json(&self.master_path, &master);
 
         let mut cache_lock = self.master_cache.write().unwrap();
         cache_lock.0 = master;
@@ -143,8 +168,13 @@ impl MemoryState {
     }
 
     pub fn rebuild_index(&self) {
-        if let Ok(new_idx) = MemoryIndex::new() {
-            let full = self.get_full_graph();
+        if let Ok(new_idx) = MemoryIndex::new(&self.base_dir) {
+            let session = self.session_graph.read().unwrap();
+            let mut full = {
+                let cache = self.master_cache.read().unwrap();
+                cache.0.clone()
+            };
+            Self::merge_graphs(&mut full, &session);
             for e in full.entities.values() {
                 let _ = new_idx.index_entity(e);
             }