Make remember tool instructions more imperative in system prompts

- Change 'call remember' to 'you MUST call remember' in native prompt
- Change 'IF you discovered' to 'ALWAYS...when you discovered'
- Add explicit list of trigger tools (code_search, rg, grep, find, read_file)
- Add reminder to Response Guidelines section
- Add remember tool and Project Memory section to non-native prompt
- Remove redundant console output from remember tool
- Fix test compilation errors (missing summary parameter, temporary borrow)

crates/g3-core/src/session_continuation.rs

@@ -481,6 +481,7 @@ mod tests {
             None,
             "test_session_123".to_string(),
             Some("Task completed successfully".to_string()),
+            None,
             "/path/to/session.json".to_string(),
             45.0,
             Some("- [x] Task 1\n- [ ] Task 2".to_string()),
@@ -499,6 +500,7 @@ mod tests {
             None,
             "test".to_string(),
             None,
+            None,
             "path".to_string(),
             50.0,
             None,
@@ -521,6 +523,7 @@ mod tests {
             Some("fowler".to_string()),
             "test".to_string(),
             None,
+            None,
             "path".to_string(),
             50.0,
             Some("- [x] Done\n- [ ] Not done".to_string()),