feat(memory): add session_id isolation to Memory trait (#530)

* feat(memory): add session_id isolation to Memory trait

Add optional session_id parameter to store(), recall(), and list()
methods across the Memory trait and all four backends (sqlite, markdown,
lucid, none). This enables per-session memory isolation so different
agent sessions cannot cross-read each other's stored memories.

Changes:
- traits.rs: Add session_id: Option<&str> to store/recall/list
- sqlite.rs: Schema migration (ALTER TABLE ADD COLUMN session_id),
  index, persist/filter by session_id in all query paths
- markdown.rs, lucid.rs, none.rs: Updated signatures
- All callers pass None for backward compatibility
- 5 new tests: session-filtered recall, cross-session isolation,
  session-filtered list, no-filter returns all, migration idempotency

Closes #518

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(channels): fix discord _channel_id typo and lark missing reply_to

Pre-existing compilation errors on main after reply_to was added to
ChannelMessage: discord.rs used _channel_id (underscore prefix) but
referenced channel_id, and lark.rs was missing the reply_to field.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/agent/agent.rs

@@ -389,7 +389,7 @@ impl Agent {
         if self.auto_save {
             let _ = self
                 .memory
-                .store("user_msg", user_message, MemoryCategory::Conversation)
+                .store("user_msg", user_message, MemoryCategory::Conversation, None)
                 .await;
         }
 
@@ -448,7 +448,7 @@ impl Agent {
                     let summary = truncate_with_ellipsis(&final_text, 100);
                     let _ = self
                         .memory
-                        .store("assistant_resp", &summary, MemoryCategory::Daily)
+                        .store("assistant_resp", &summary, MemoryCategory::Daily, None)
                         .await;
                 }
 

src/agent/loop_.rs

@@ -145,7 +145,7 @@ async fn build_context(mem: &dyn Memory, user_msg: &str) -> String {
     let mut context = String::new();
 
     // Pull relevant memories for this message
-    if let Ok(entries) = mem.recall(user_msg, 5).await {
+    if let Ok(entries) = mem.recall(user_msg, 5, None).await {
         if !entries.is_empty() {
             context.push_str("[Memory context]\n");
             for entry in &entries {
@@ -913,7 +913,7 @@ pub async fn run(
         if config.memory.auto_save {
             let user_key = autosave_memory_key("user_msg");
             let _ = mem
-                .store(&user_key, &msg, MemoryCategory::Conversation)
+                .store(&user_key, &msg, MemoryCategory::Conversation, None)
                 .await;
         }
 
@@ -956,7 +956,7 @@ pub async fn run(
             let summary = truncate_with_ellipsis(&response, 100);
             let response_key = autosave_memory_key("assistant_resp");
             let _ = mem
-                .store(&response_key, &summary, MemoryCategory::Daily)
+                .store(&response_key, &summary, MemoryCategory::Daily, None)
                 .await;
         }
     } else {
@@ -979,7 +979,7 @@ pub async fn run(
             if config.memory.auto_save {
                 let user_key = autosave_memory_key("user_msg");
                 let _ = mem
-                    .store(&user_key, &msg.content, MemoryCategory::Conversation)
+                    .store(&user_key, &msg.content, MemoryCategory::Conversation, None)
                     .await;
             }
 
@@ -1037,7 +1037,7 @@ pub async fn run(
                 let summary = truncate_with_ellipsis(&response, 100);
                 let response_key = autosave_memory_key("assistant_resp");
                 let _ = mem
-                    .store(&response_key, &summary, MemoryCategory::Daily)
+                    .store(&response_key, &summary, MemoryCategory::Daily, None)
                     .await;
             }
         }
@@ -1499,16 +1499,16 @@ I will now call the tool with this payload:
         let key1 = autosave_memory_key("user_msg");
         let key2 = autosave_memory_key("user_msg");
 
-        mem.store(&key1, "I'm Paul", MemoryCategory::Conversation)
+        mem.store(&key1, "I'm Paul", MemoryCategory::Conversation, None)
             .await
             .unwrap();
-        mem.store(&key2, "I'm 45", MemoryCategory::Conversation)
+        mem.store(&key2, "I'm 45", MemoryCategory::Conversation, None)
             .await
             .unwrap();
 
         assert_eq!(mem.count().await.unwrap(), 2);
 
-        let recalled = mem.recall("45", 5).await.unwrap();
+        let recalled = mem.recall("45", 5, None).await.unwrap();
         assert!(recalled.iter().any(|entry| entry.content.contains("45")));
     }
 

src/agent/memory_loader.rs

@@ -33,7 +33,7 @@ impl MemoryLoader for DefaultMemoryLoader {
         memory: &dyn Memory,
         user_message: &str,
     ) -> anyhow::Result<String> {
-        let entries = memory.recall(user_message, self.limit).await?;
+        let entries = memory.recall(user_message, self.limit, None).await?;
         if entries.is_empty() {
             return Ok(String::new());
         }
@@ -61,11 +61,17 @@ mod tests {
             _key: &str,
             _content: &str,
             _category: MemoryCategory,
+            _session_id: Option<&str>,
         ) -> anyhow::Result<()> {
             Ok(())
         }
 
-        async fn recall(&self, _query: &str, limit: usize) -> anyhow::Result<Vec<MemoryEntry>> {
+        async fn recall(
+            &self,
+            _query: &str,
+            limit: usize,
+            _session_id: Option<&str>,
+        ) -> anyhow::Result<Vec<MemoryEntry>> {
             if limit == 0 {
                 return Ok(vec![]);
             }
@@ -87,6 +93,7 @@ mod tests {
         async fn list(
             &self,
             _category: Option<&MemoryCategory>,
+            _session_id: Option<&str>,
         ) -> anyhow::Result<Vec<MemoryEntry>> {
             Ok(vec![])
         }