Remove Anthropic API key authentication support

API key auth only provides short-lived session tokens (8hrs or until
session restart) with no refresh mechanism, unlike OAuth which persists
via .credentials.json. Remove the non-functional API key settings UI
and all supporting code (frontend state, Tauri commands, keyring
storage, container env var injection, and fingerprint-based recreation
checks) to avoid user confusion.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src-tauri/src/storage/secure.rs

@@ -1,42 +1,3 @@
-const SERVICE_NAME: &str = "triple-c";
-const API_KEY_USER: &str = "anthropic-api-key";
-
-pub fn store_api_key(key: &str) -> Result<(), String> {
-    let entry = keyring::Entry::new(SERVICE_NAME, API_KEY_USER)
-        .map_err(|e| format!("Keyring error: {}", e))?;
-    entry
-        .set_password(key)
-        .map_err(|e| format!("Failed to store API key: {}", e))
-}
-
-pub fn get_api_key() -> Result<Option<String>, String> {
-    let entry = keyring::Entry::new(SERVICE_NAME, API_KEY_USER)
-        .map_err(|e| format!("Keyring error: {}", e))?;
-    match entry.get_password() {
-        Ok(key) => Ok(Some(key)),
-        Err(keyring::Error::NoEntry) => Ok(None),
-        Err(e) => Err(format!("Failed to retrieve API key: {}", e)),
-    }
-}
-
-pub fn delete_api_key() -> Result<(), String> {
-    let entry = keyring::Entry::new(SERVICE_NAME, API_KEY_USER)
-        .map_err(|e| format!("Keyring error: {}", e))?;
-    match entry.delete_credential() {
-        Ok(()) => Ok(()),
-        Err(keyring::Error::NoEntry) => Ok(()),
-        Err(e) => Err(format!("Failed to delete API key: {}", e)),
-    }
-}
-
-pub fn has_api_key() -> Result<bool, String> {
-    match get_api_key() {
-        Ok(Some(_)) => Ok(true),
-        Ok(None) => Ok(false),
-        Err(e) => Err(e),
-    }
-}
-
 /// Store a per-project secret in the OS keychain.
 pub fn store_project_secret(project_id: &str, key_name: &str, value: &str) -> Result<(), String> {
     let service = format!("triple-c-project-{}-{}", project_id, key_name);