feat: add persistent memory system + SQLite session store

Two-part implementation:

Part A - Curated Bounded Memory:
- New memory tool (tools/memory_tool.py) with MEMORY.md + USER.md stores
- Character-limited (2200/1375 chars), § delimited entries
- Frozen snapshot injected into system prompt at session start
- Model manages pruning via replace/remove with substring matching
- Usage indicator shown in system prompt header

Part B - SQLite Session Store:
- New hermes_state.py with SessionDB class, FTS5 full-text search
- Gateway session.py rewritten to dual-write SQLite + legacy JSONL
- Compression-triggered session splitting with parent_session_id chains
- New session_search tool with Gemini Flash summarization of matched sessions
- CLI session lifecycle (create on launch, close on exit)

Also:
- System prompt now cached per session, only rebuilt on compression
  (fixes prefix cache invalidation from date/time changes every turn)
- Config version bumped to 3, hermes doctor checks for new artifacts
- Disabled in batch_runner and RL environments

toolsets.py

@@ -120,6 +120,19 @@ TOOLSETS = {
         "includes": []
     },
     
+    "memory": {
+        "description": "Persistent memory across sessions (personal notes + user profile)",
+        "tools": ["memory"],
+        "includes": []
+    },
+    
+    "session_search": {
+        "description": "Search and recall past conversations with summarization",
+        "tools": ["session_search"],
+        "includes": []
+    },
+    
+    
     # Scenario-specific toolsets
     
     "debugging": {
@@ -164,6 +177,10 @@ TOOLSETS = {
             "text_to_speech",
             # Planning & task management
             "todo",
+            # Persistent memory
+            "memory",
+            # Session history search
+            "session_search",
             # Cronjob management (CLI-only)
             "schedule_cronjob", "list_cronjobs", "remove_cronjob"
         ],
@@ -198,6 +215,10 @@ TOOLSETS = {
             "skills_list", "skill_view",
             # Planning & task management
             "todo",
+            # Persistent memory
+            "memory",
+            # Session history search
+            "session_search",
             # Cronjob management - let users schedule tasks
             "schedule_cronjob", "list_cronjobs", "remove_cronjob",
             # Cross-channel messaging
@@ -230,6 +251,10 @@ TOOLSETS = {
             "skills_list", "skill_view",
             # Planning & task management
             "todo",
+            # Persistent memory
+            "memory",
+            # Session history search
+            "session_search",
             # Cronjob management - let users schedule tasks
             "schedule_cronjob", "list_cronjobs", "remove_cronjob",
             # Cross-channel messaging
@@ -262,6 +287,10 @@ TOOLSETS = {
             "skills_list", "skill_view",
             # Planning & task management
             "todo",
+            # Persistent memory
+            "memory",
+            # Session history search
+            "session_search",
             # Cronjob management
             "schedule_cronjob", "list_cronjobs", "remove_cronjob",
             # Cross-channel messaging
@@ -294,6 +323,10 @@ TOOLSETS = {
             "skills_list", "skill_view",
             # Planning & task management
             "todo",
+            # Persistent memory
+            "memory",
+            # Session history search
+            "session_search",
             # Cronjob management - let users schedule tasks
             "schedule_cronjob", "list_cronjobs", "remove_cronjob",
             # Cross-channel messaging