Isolate dev/prod app data to prevent clashes

Running dev (`pnpm dev`) and prod (installed .app) on the same machine caused
`database is locked` errors, MCP port bind failures, and shared state corruption
because both used the same `~/Library/Application Support/com.veszelovszki.cmdr/`.

- Add `resolved_app_data_dir()` helper that appends `-dev` to the data directory in debug builds (→ `com.veszelovszki.cmdr-dev/`). Replace all 6 `app_data_dir()` call sites: indexing, settings, AI, font metrics, known shares.
- Use MCP port 9225 in dev (prod keeps 9224) to prevent port conflicts.
- Update `.mcp.json` and `.claude/settings.json` to match the dev port.
- Logs stay shared intentionally — useful for cross-environment debugging.

Author: vdavid

.claude/settings.json

@@ -1,7 +1,7 @@
 {
   "mcpServers": {
     "cmdr": {
-      "url": "http://localhost:9224/mcp"
+      "url": "http://localhost:9225/mcp"
     }
   },
   "hooks": {

.mcp.json

@@ -2,7 +2,7 @@
   "mcpServers": {
     "cmdr": {
       "type": "http",
-      "url": "http://127.0.0.1:9224/mcp"
+      "url": "http://127.0.0.1:9225/mcp"
     },
     "tauri": {
       "type": "stdio",

apps/desktop/src-tauri/src/ai/manager.rs

@@ -18,7 +18,7 @@ use std::fs;
 use std::path::{Path, PathBuf};
 use std::sync::Mutex;
 use std::time::{SystemTime, UNIX_EPOCH};
-use tauri::{AppHandle, Emitter, Manager, Runtime};
+use tauri::{AppHandle, Emitter, Runtime};
 
 /// Global manager state, accessible from Tauri commands.
 static MANAGER: Mutex<Option<ManagerState>> = Mutex::new(None);
@@ -341,8 +341,7 @@ fn get_current_model() -> &'static ModelInfo {
 }
 
 fn get_ai_dir<R: Runtime>(app: &AppHandle<R>) -> PathBuf {
-    app.path()
-        .app_data_dir()
+    crate::config::resolved_app_data_dir(app)
         .unwrap_or_else(|_| PathBuf::from("."))
         .join("ai")
 }

apps/desktop/src-tauri/src/config.rs

@@ -1,7 +1,10 @@
-//! Configuration constants.
+//! Configuration constants and path helpers.
 //!
 //! These can be extracted to environment variables or a config file in the future.
 
+use std::path::PathBuf;
+use tauri::{AppHandle, Manager, Runtime};
+
 /// Icon size in pixels (32x32 for retina display)
 pub const ICON_SIZE: u32 = 32;
 
@@ -15,6 +18,36 @@ pub const ICON_SIZE: u32 = 32;
 /// TODO: Move this to a setting once we have a settings window in place
 pub const USE_APP_ICONS_AS_DOCUMENT_ICONS: bool = true;
 
+/// Returns the app data directory, with a `-dev` suffix in debug builds to isolate
+/// dev and prod data (databases, caches, AI models). Creates the directory if needed.
+pub fn resolved_app_data_dir<R: Runtime>(app: &AppHandle<R>) -> Result<PathBuf, String> {
+    let base = app
+        .path()
+        .app_data_dir()
+        .map_err(|e| format!("Failed to get app data dir: {e}"))?;
+
+    let dir = if cfg!(debug_assertions) {
+        let mut name = base.file_name().unwrap_or_default().to_os_string();
+        name.push("-dev");
+        base.with_file_name(name)
+    } else {
+        base
+    };
+
+    std::fs::create_dir_all(&dir).map_err(|e| format!("Failed to create app data dir: {e}"))?;
+
+    Ok(dir)
+}
+
+/// Logs the resolved data directory once at startup.
+pub fn log_app_data_dir<R: Runtime>(app: &AppHandle<R>) {
+    if cfg!(debug_assertions)
+        && let Ok(dir) = resolved_app_data_dir(app)
+    {
+        log::debug!("Using dev app data dir: {}", dir.display());
+    }
+}
+
 // MCP Server Security Design:
 // --------------------------
 // The MCP (Model Context Protocol) bridge allows AI assistants to control the app.

apps/desktop/src-tauri/src/font_metrics/CLAUDE.md

@@ -55,5 +55,6 @@ METRICS_CACHE: LazyLock<RwLock<HashMap<String, FontMetrics>>>
 
 ## Dependencies
 
-External: `bincode2`, `tauri::Manager`
+External: `bincode2`
+Internal: `crate::config::resolved_app_data_dir`
 Internal: none

apps/desktop/src-tauri/src/font_metrics/mod.rs

@@ -8,7 +8,6 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::fs;
 use std::sync::{LazyLock, RwLock};
-use tauri::Manager;
 
 /// Cache for font metrics, keyed by font ID (like "system-400-12")
 static METRICS_CACHE: LazyLock<RwLock<HashMap<String, FontMetrics>>> = LazyLock::new(|| RwLock::new(HashMap::new()));
@@ -95,7 +94,7 @@ pub fn calculate_max_width(texts: &[&str], font_id: &str) -> Option<f32> {
 
 /// Loads font metrics from disk
 pub fn load_from_disk<R: tauri::Runtime>(app: &tauri::AppHandle<R>, font_id: &str) -> Option<FontMetrics> {
-    let data_dir = app.path().app_data_dir().ok()?;
+    let data_dir = crate::config::resolved_app_data_dir(app).ok()?;
     let metrics_dir = data_dir.join("font-metrics");
     let file_path = metrics_dir.join(format!("{}.bin", font_id));
 
@@ -109,10 +108,7 @@ pub fn save_to_disk<R: tauri::Runtime>(
     font_id: &str,
     widths: &HashMap<u32, f32>,
 ) -> Result<(), String> {
-    let data_dir = app
-        .path()
-        .app_data_dir()
-        .map_err(|e| format!("Failed to get app data dir: {}", e))?;
+    let data_dir = crate::config::resolved_app_data_dir(app)?;
     let metrics_dir = data_dir.join("font-metrics");
 
     // Create directory if it doesn't exist

apps/desktop/src-tauri/src/indexing/mod.rs

@@ -307,13 +307,7 @@ impl IndexManager {
     /// Opens (or creates) the SQLite database, spawns the writer thread,
     /// and sets up the micro-scan manager.
     pub fn new(volume_id: String, volume_root: PathBuf, app: AppHandle) -> Result<Self, String> {
-        let data_dir = app
-            .path()
-            .app_data_dir()
-            .map_err(|e| format!("Failed to get app data dir: {e}"))?;
-
-        // Ensure the data directory exists
-        std::fs::create_dir_all(&data_dir).map_err(|e| format!("Failed to create app data dir: {e}"))?;
+        let data_dir = crate::config::resolved_app_data_dir(&app)?;
 
         let db_path = data_dir.join(format!("index-{volume_id}.db"));
 

apps/desktop/src-tauri/src/lib.rs

@@ -253,6 +253,9 @@ pub fn run() {
                 log::set_max_level(log::LevelFilter::Info);
             }
 
+            // Log the resolved app data directory (shows -dev suffix in debug builds)
+            config::log_app_data_dir(app.handle());
+
             // Initialize benchmarking (enabled by RUSTY_COMMANDER_BENCHMARK=1)
             benchmark::init_benchmarking();
 

apps/desktop/src-tauri/src/mcp/CLAUDE.md

@@ -9,7 +9,7 @@ Expose Cmdr functionality to AI agents via the Model Context Protocol (MCP). Age
 ### Server (`server.rs`)
 
 - Runs in a background tokio task spawned at app startup
-- Binds to `127.0.0.1:9224` (localhost only for security)
+- Binds to `127.0.0.1:9225` in dev, `127.0.0.1:9224` in release (localhost only for security)
 - Streamable HTTP transport (MCP spec 2025-11-25)
 - Endpoints: `POST /mcp` (JSON-RPC), `GET /mcp` (optional SSE), `GET /mcp/health`
 

apps/desktop/src-tauri/src/mcp/config.rs

@@ -36,12 +36,13 @@ impl McpConfig {
         // Priority for port:
         // 1. CMDR_MCP_PORT env var (explicit dev override)
         // 2. User setting (developer.mcpPort)
-        // 3. Default: 9224
+        // 3. Default: 9225 in debug builds, 9224 in release
+        let default_port: u16 = if cfg!(debug_assertions) { 9225 } else { 9224 };
         let port = env::var("CMDR_MCP_PORT")
             .ok()
             .and_then(|v| v.parse().ok())
             .or(setting_port)
-            .unwrap_or(9224);
+            .unwrap_or(default_port);
 
         Self { enabled, port }
     }
@@ -61,10 +62,10 @@ mod tests {
     fn test_direct_construction() {
         let config = McpConfig {
             enabled: true,
-            port: 9224,
+            port: 9225,
         };
 
-        assert_eq!(config.port, 9224);
+        assert_eq!(config.port, 9225);
         assert!(config.enabled);
     }
 
@@ -84,6 +85,10 @@ mod tests {
     fn test_from_settings_with_no_settings() {
         // When no settings are provided, should use defaults
         let config = McpConfig::from_settings_and_env(None, None);
+        // Debug builds use port 9225 to avoid clashing with a running release build
+        #[cfg(debug_assertions)]
+        assert_eq!(config.port, 9225);
+        #[cfg(not(debug_assertions))]
         assert_eq!(config.port, 9224);
         // In debug builds, enabled is true by default
         #[cfg(debug_assertions)]