feat: enhance agent personality, tool guidance, and memory hygiene

- Expand communication style presets (professional, expressive, custom)
- Enrich SOUL.md with human-like tone and emoji-awareness guidance
- Add crash recovery and sub-task scoping guidance to AGENTS.md scaffold
- Add 'Use when / Don't use when' guidance to TOOLS.md and runtime prompts
- Implement memory hygiene system with configurable archiving and retention
- Add MemoryConfig options: hygiene_enabled, archive_after_days, purge_after_days, conversation_retention_days
- Archive old daily memory and session files to archive subdirectories
- Purge old archives and prune stale SQLite conversation rows
- Add comprehensive tests for new features

src/runtime/mod.rs

@@ -7,17 +7,21 @@ pub use traits::RuntimeAdapter;
 use crate::config::RuntimeConfig;
 
 /// Factory: create the right runtime from config
-pub fn create_runtime(config: &RuntimeConfig) -> Box<dyn RuntimeAdapter> {
+pub fn create_runtime(config: &RuntimeConfig) -> anyhow::Result<Box<dyn RuntimeAdapter>> {
     match config.kind.as_str() {
-        "native" | "docker" => Box::new(NativeRuntime::new()),
-        "cloudflare" => {
-            tracing::warn!("Cloudflare runtime not yet implemented, falling back to native");
-            Box::new(NativeRuntime::new())
-        }
-        _ => {
-            tracing::warn!("Unknown runtime '{}', falling back to native", config.kind);
-            Box::new(NativeRuntime::new())
-        }
+        "native" => Ok(Box::new(NativeRuntime::new())),
+        "docker" => anyhow::bail!(
+            "runtime.kind='docker' is not implemented yet. Use runtime.kind='native' until container runtime support lands."
+        ),
+        "cloudflare" => anyhow::bail!(
+            "runtime.kind='cloudflare' is not implemented yet. Use runtime.kind='native' for now."
+        ),
+        other if other.trim().is_empty() => anyhow::bail!(
+            "runtime.kind cannot be empty. Supported values: native"
+        ),
+        other => anyhow::bail!(
+            "Unknown runtime kind '{other}'. Supported values: native"
+        ),
     }
 }
 
@@ -30,44 +34,52 @@ mod tests {
         let cfg = RuntimeConfig {
             kind: "native".into(),
         };
-        let rt = create_runtime(&cfg);
+        let rt = create_runtime(&cfg).unwrap();
         assert_eq!(rt.name(), "native");
         assert!(rt.has_shell_access());
     }
 
     #[test]
-    fn factory_docker_returns_native() {
+    fn factory_docker_errors() {
         let cfg = RuntimeConfig {
             kind: "docker".into(),
         };
-        let rt = create_runtime(&cfg);
-        assert_eq!(rt.name(), "native");
+        match create_runtime(&cfg) {
+            Err(err) => assert!(err.to_string().contains("not implemented")),
+            Ok(_) => panic!("docker runtime should error"),
+        }
     }
 
     #[test]
-    fn factory_cloudflare_falls_back() {
+    fn factory_cloudflare_errors() {
         let cfg = RuntimeConfig {
             kind: "cloudflare".into(),
         };
-        let rt = create_runtime(&cfg);
-        assert_eq!(rt.name(), "native");
+        match create_runtime(&cfg) {
+            Err(err) => assert!(err.to_string().contains("not implemented")),
+            Ok(_) => panic!("cloudflare runtime should error"),
+        }
     }
 
     #[test]
-    fn factory_unknown_falls_back() {
+    fn factory_unknown_errors() {
         let cfg = RuntimeConfig {
             kind: "wasm-edge-unknown".into(),
         };
-        let rt = create_runtime(&cfg);
-        assert_eq!(rt.name(), "native");
+        match create_runtime(&cfg) {
+            Err(err) => assert!(err.to_string().contains("Unknown runtime kind")),
+            Ok(_) => panic!("unknown runtime should error"),
+        }
     }
 
     #[test]
-    fn factory_empty_falls_back() {
+    fn factory_empty_errors() {
         let cfg = RuntimeConfig {
             kind: String::new(),
         };
-        let rt = create_runtime(&cfg);
-        assert_eq!(rt.name(), "native");
+        match create_runtime(&cfg) {
+            Err(err) => assert!(err.to_string().contains("cannot be empty")),
+            Ok(_) => panic!("empty runtime should error"),
+        }
     }
 }