feat(rebrand): rename binary to trcaa and auto-generate DB key

- Rename Cargo package from 'tftsr' to 'trcaa' — installed command
  becomes 'trcaa' instead of 'tftsr'
- Update app data directories to ~/.local/share/trcaa (Linux),
  ~/Library/Application Support/trcaa (macOS), %APPDATA%/trcaa (Windows)
- Update bundle identifier to com.trcaa.app
- Auto-generate per-installation DB encryption key on first launch and
  persist to <data_dir>/.dbkey (mode 0600 on Unix) — removes the hard
  requirement for TFTSR_DB_KEY to be set before the app will start

src-tauri/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "tftsr"
+name = "trcaa"
 version = "0.1.0"
 edition = "2021"
 

src-tauri/src/db/connection.rs

@@ -1,7 +1,34 @@
 use rusqlite::Connection;
 use std::path::Path;
 
-fn get_db_key() -> anyhow::Result<String> {
+fn generate_key() -> String {
+    use rand::RngCore;
+    let mut bytes = [0u8; 32];
+    rand::rngs::OsRng.fill_bytes(&mut bytes);
+    hex::encode(bytes)
+}
+
+#[cfg(unix)]
+fn write_key_file(path: &Path, key: &str) -> anyhow::Result<()> {
+    use std::io::Write;
+    use std::os::unix::fs::OpenOptionsExt;
+    let mut f = std::fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .mode(0o600)
+        .open(path)?;
+    f.write_all(key.as_bytes())?;
+    Ok(())
+}
+
+#[cfg(not(unix))]
+fn write_key_file(path: &Path, key: &str) -> anyhow::Result<()> {
+    std::fs::write(path, key)?;
+    Ok(())
+}
+
+fn get_db_key(data_dir: &Path) -> anyhow::Result<String> {
     if let Ok(key) = std::env::var("TFTSR_DB_KEY") {
         if !key.trim().is_empty() {
             return Ok(key);
@@ -12,9 +39,22 @@ fn get_db_key() -> anyhow::Result<String> {
         return Ok("dev-key-change-in-prod".to_string());
     }
 
-    Err(anyhow::anyhow!(
-        "TFTSR_DB_KEY must be set in release builds"
-    ))
+    // Release: load or auto-generate a per-installation key stored in the
+    // app data directory. This lets the app work out of the box without
+    // requiring users to set an environment variable.
+    let key_path = data_dir.join(".dbkey");
+    if key_path.exists() {
+        let key = std::fs::read_to_string(&key_path)?;
+        let key = key.trim().to_string();
+        if !key.is_empty() {
+            return Ok(key);
+        }
+    }
+
+    let key = generate_key();
+    std::fs::create_dir_all(data_dir)?;
+    write_key_file(&key_path, &key)?;
+    Ok(key)
 }
 
 pub fn open_encrypted_db(path: &Path, key: &str) -> anyhow::Result<Connection> {
@@ -45,8 +85,7 @@ pub fn init_db(data_dir: &Path) -> anyhow::Result<Connection> {
     std::fs::create_dir_all(data_dir)?;
     let db_path = data_dir.join("tftsr.db");
 
-    // In dev/test mode use unencrypted DB; in production use encryption
-    let key = get_db_key()?;
+    let key = get_db_key(data_dir)?;
 
     let conn = if cfg!(debug_assertions) {
         open_dev_db(&db_path)?
@@ -62,18 +101,26 @@ pub fn init_db(data_dir: &Path) -> anyhow::Result<Connection> {
 mod tests {
     use super::*;
 
+    fn temp_dir(name: &str) -> std::path::PathBuf {
+        let dir = std::env::temp_dir().join(format!("tftsr-test-{}", name));
+        std::fs::create_dir_all(&dir).unwrap();
+        dir
+    }
+
     #[test]
     fn test_get_db_key_uses_env_var_when_present() {
+        let dir = temp_dir("env-var");
         std::env::set_var("TFTSR_DB_KEY", "test-db-key");
-        let key = get_db_key().unwrap();
+        let key = get_db_key(&dir).unwrap();
         assert_eq!(key, "test-db-key");
         std::env::remove_var("TFTSR_DB_KEY");
     }
 
     #[test]
     fn test_get_db_key_debug_fallback_for_empty_env() {
+        let dir = temp_dir("empty-env");
         std::env::set_var("TFTSR_DB_KEY", "   ");
-        let key = get_db_key().unwrap();
+        let key = get_db_key(&dir).unwrap();
         assert_eq!(key, "dev-key-change-in-prod");
         std::env::remove_var("TFTSR_DB_KEY");
     }

src-tauri/src/lib.rs

@@ -124,13 +124,13 @@ fn dirs_data_dir() -> std::path::PathBuf {
     #[cfg(target_os = "linux")]
     {
         if let Ok(xdg) = std::env::var("XDG_DATA_HOME") {
-            return std::path::PathBuf::from(xdg).join("tftsr");
+            return std::path::PathBuf::from(xdg).join("trcaa");
         }
         if let Ok(home) = std::env::var("HOME") {
             return std::path::PathBuf::from(home)
                 .join(".local")
                 .join("share")
-                .join("tftsr");
+                .join("trcaa");
         }
     }
 
@@ -140,17 +140,17 @@ fn dirs_data_dir() -> std::path::PathBuf {
             return std::path::PathBuf::from(home)
                 .join("Library")
                 .join("Application Support")
-                .join("tftsr");
+                .join("trcaa");
         }
     }
 
     #[cfg(target_os = "windows")]
     {
         if let Ok(appdata) = std::env::var("APPDATA") {
-            return std::path::PathBuf::from(appdata).join("tftsr");
+            return std::path::PathBuf::from(appdata).join("trcaa");
         }
     }
 
     // Fallback
-    std::path::PathBuf::from("./tftsr-data")
+    std::path::PathBuf::from("./trcaa-data")
 }

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "productName": "Troubleshooting and RCA Assistant",
   "version": "0.2.10",
-  "identifier": "com.tftsr.devops",
+  "identifier": "com.trcaa.app",
   "build": {
     "frontendDist": "../dist",
     "devUrl": "http://localhost:1420",