chore(hardening): tighten security and footprint defaults

crates/core/src/paths.rs

@@ -0,0 +1,125 @@
+use std::path::PathBuf;
+
+use crate::types::ModelId;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AppPaths {
+    app_data_dir: PathBuf,
+}
+
+impl AppPaths {
+    pub fn current() -> Self {
+        Self {
+            app_data_dir: resolve_app_data_dir(),
+        }
+    }
+
+    pub fn app_data_dir(&self) -> PathBuf {
+        self.app_data_dir.clone()
+    }
+
+    pub fn database_path(&self) -> PathBuf {
+        self.app_data_dir.join("kon.db")
+    }
+
+    pub fn recordings_dir(&self) -> PathBuf {
+        self.app_data_dir.join("recordings")
+    }
+
+    pub fn crashes_dir(&self) -> PathBuf {
+        self.app_data_dir.join("crashes")
+    }
+
+    pub fn logs_dir(&self) -> PathBuf {
+        self.app_data_dir.join("logs")
+    }
+
+    pub fn diagnostic_reports_dir(&self) -> PathBuf {
+        self.app_data_dir.join("diagnostic-reports")
+    }
+
+    pub fn models_dir(&self) -> PathBuf {
+        self.app_data_dir.join("models")
+    }
+
+    pub fn speech_model_dir(&self, id: &ModelId) -> PathBuf {
+        self.models_dir().join(id.as_str())
+    }
+
+    pub fn llm_models_dir(&self) -> PathBuf {
+        self.models_dir().join("llm")
+    }
+
+    pub fn migration_sentinel(&self, name: &str) -> PathBuf {
+        self.app_data_dir.join(format!(".{name}.sentinel"))
+    }
+}
+
+pub fn app_paths() -> AppPaths {
+    AppPaths::current()
+}
+
+pub fn app_data_dir() -> PathBuf {
+    app_paths().app_data_dir()
+}
+
+fn resolve_app_data_dir() -> PathBuf {
+    #[cfg(target_os = "windows")]
+    {
+        let local_app_data = std::env::var("LOCALAPPDATA").unwrap_or_else(|_| ".".to_string());
+        return PathBuf::from(local_app_data).join("kon");
+    }
+
+    #[cfg(target_os = "macos")]
+    {
+        let home = std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string());
+        return PathBuf::from(home)
+            .join("Library")
+            .join("Application Support")
+            .join("Kon");
+    }
+
+    #[cfg(target_os = "linux")]
+    {
+        let home = std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string());
+        let legacy = PathBuf::from(&home).join(".kon");
+        if legacy.exists() {
+            return legacy;
+        }
+        if let Ok(xdg) = std::env::var("XDG_DATA_HOME") {
+            if !xdg.is_empty() {
+                return PathBuf::from(xdg).join("kon");
+            }
+        }
+        PathBuf::from(home).join(".local").join("share").join("kon")
+    }
+
+    #[cfg(not(any(target_os = "windows", target_os = "macos", target_os = "linux")))]
+    {
+        let home = std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string());
+        PathBuf::from(home).join(".kon")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::AppPaths;
+    use crate::types::ModelId;
+    use std::path::PathBuf;
+
+    #[test]
+    fn derives_all_paths_from_one_base() {
+        let paths = AppPaths {
+            app_data_dir: PathBuf::from("/tmp/kon-test"),
+        };
+        assert_eq!(paths.database_path(), PathBuf::from("/tmp/kon-test/kon.db"));
+        assert_eq!(
+            paths.speech_model_dir(&ModelId::new("whisper-base-en")),
+            PathBuf::from("/tmp/kon-test/models/whisper-base-en")
+        );
+        assert_eq!(
+            paths.llm_models_dir(),
+            PathBuf::from("/tmp/kon-test/models/llm")
+        );
+    }
+}