feat(one): add settings window for environment variable configuration

Author: os-zhuang

apps/objectos-one/README.md

@@ -43,6 +43,32 @@ The sidecar receives `OBJECTOS_HOME`, `OS_DATABASE_URL`,
 `OS_STORAGE_ROOT`, and `OS_CACHE_DIR` pointed inside that folder, so a
 clean uninstall is just deleting that directory.
 
+## Configuration
+
+Open **tray → Settings…** to edit environment variables passed to the
+ObjectOS server. Variables are stored in `<data-dir>/one.config.json` as
+a flat map and forwarded verbatim when the runtime starts.
+
+Commonly used keys:
+
+| Key             | Default          | Notes                                                            |
+|-----------------|------------------|------------------------------------------------------------------|
+| `PORT`          | auto (3000+)     | Fixed port. If in use, falls back to auto with a log line.       |
+| `HOST`          | `127.0.0.1`      | `0.0.0.0` exposes the server to the LAN. **Set up auth first.**  |
+| `OBJECTOS_HOME` | `~/.objectstack` | Data directory. Absolute path.                                   |
+| `LOG_LEVEL`     | —                | Forwarded to the Node server.                                    |
+| _anything else_ | —                | Forwarded as-is to the sidecar process.                          |
+
+The Settings window also reflects values inherited from the parent
+shell — those win over the saved file, so a one-off override still
+works:
+
+```
+PORT=4001 HOST=0.0.0.0 open -a ObjectOS
+```
+
+Save in the Settings window triggers an automatic runtime restart.
+
 ## Prerequisites
 
 -  20 + pnpm 10Node 

apps/objectos-one/src-tauri/src/config.rs

@@ -0,0 +1,136 @@
+//! User configuration for ObjectOS One.
+//!
+//! Model: a flat map of environment variables that get merged into the
+//! sidecar process. This intentionally avoids hard-coding "known" config
+//! fields — anything the Node server reads from env is configurable.
+//!
+//! Resolution order (later overrides earlier) for the values handed to the
+//! sidecar:
+//!   1. Inherited process env (parent shell)
+//!   2. `one.config.json` `env` map (user-edited via Settings window)
+//!   3. Explicit `OBJECTOS_*` env vars in the parent shell (always win,
+//!      so a one-off `OBJECTOS_PORT=4001 open -a ObjectOS` overrides the
+//!      saved config)
+
+use std::{collections::BTreeMap, fs, path::PathBuf};
+
+use serde::{Deserialize, Serialize};
+
+pub const CONFIG_FILE: &str = "one.config.json";
+
+/// Persisted user configuration. `env` is the only field on purpose —
+/// keeping the schema flat means new server-side env vars don't require any
+/// shell change.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+pub struct StoredConfig {
+    /// Environment variables to pass to the sidecar. BTreeMap so the file
+    /// stays diff-friendly (sorted keys).
+    #[serde(default)]
+    pub env: BTreeMap<String, String>,
+}
+
+/// Defaults for the data dir when nothing is set.
+pub fn default_data_dir() -> PathBuf {
+    let mut p = dirs::home_dir().expect("home dir");
+    p.push(".objectstack");
+    p
+}
+
+/// Path to the JSON config file. Lives next to the user data dir so a clean
+/// uninstall (rm of data dir) also clears the config.
+pub fn config_file_path() -> PathBuf {
+    let base = std::env::var("OBJECTOS_HOME")
+        .map(PathBuf::from)
+        .unwrap_or_else(default_data_dir);
+    base.join(CONFIG_FILE)
+}
+
+/// Read the config file. Missing → empty config. Malformed → empty config
+/// (with a warning) so a typo never bricks the app.
+pub fn load() -> StoredConfig {
+    let path = config_file_path();
+    let Ok(raw) = fs::read_to_string(&path) else {
+        return StoredConfig::default();
+    };
+    match serde_json::from_str::<StoredConfig>(&raw) {
+        Ok(cfg) => cfg,
+        Err(e) => {
+            eprintln!(
+                "[one] config: ignoring malformed {} ({e}); using defaults",
+                path.display()
+            );
+            StoredConfig::default()
+        }
+    }
+}
+
+/// Persist the StoredConfig to disk (pretty-printed for hand-edits).
+pub fn save(cfg: &StoredConfig) -> std::io::Result<PathBuf> {
+    let path = config_file_path();
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    let json = serde_json::to_string_pretty(cfg)
+        .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+    fs::write(&path, json + "\n")?;
+    Ok(path)
+}
+
+/// Read an effective env var with the same resolution the sidecar will see.
+/// Useful for Rust-side decisions (port binding, data dir creation) that
+/// must agree with what the Node process gets.
+pub fn effective(key: &str) -> Option<String> {
+    // Parent-shell value wins so debug overrides always work.
+    if let Ok(v) = std::env::var(key) {
+        if !v.is_empty() {
+            return Some(v);
+        }
+    }
+    load().env.get(key).cloned()
+}
+
+/// Convenience: parse an env var as u16.
+pub fn effective_u16(key: &str) -> Option<u16> {
+    effective(key).and_then(|s| s.parse().ok())
+}
+
+/// Effective host the sidecar will bind to. Default: 127.0.0.1.
+pub fn effective_host() -> String {
+    effective("HOST").unwrap_or_else(|| "127.0.0.1".to_string())
+}
+
+/// Effective data dir. Default: ~/.objectstack.
+pub fn effective_data_dir() -> PathBuf {
+    effective("OBJECTOS_HOME")
+        .map(PathBuf::from)
+        .unwrap_or_else(default_data_dir)
+}
+
+/// Snapshot returned to the Settings window. Includes the stored map plus
+/// indicators for keys that are currently overridden by the parent shell
+/// (so the UI can show "(set in shell — saved value ignored)").
+#[derive(Debug, Clone, Serialize)]
+pub struct ConfigSnapshot {
+    pub env: BTreeMap<String, String>,
+    pub shell_overrides: BTreeMap<String, String>,
+    pub config_path: PathBuf,
+}
+
+pub fn snapshot() -> ConfigSnapshot {
+    let stored = load();
+    let mut shell_overrides = BTreeMap::new();
+    for key in stored.env.keys() {
+        if let Ok(v) = std::env::var(key) {
+            if !v.is_empty() {
+                shell_overrides.insert(key.clone(), v);
+            }
+        }
+    }
+    ConfigSnapshot {
+        env: stored.env,
+        shell_overrides,
+        config_path: config_file_path(),
+    }
+}
+
+