refactor: collapse GATEWAY_USER_ID into IRONCLAW_OWNER_ID

Remove the separate GATEWAY_USER_ID config. The gateway now uses
IRONCLAW_OWNER_ID (config.owner_id) directly for auth identity,
bootstrap user creation, and workspace scoping.

Previously, with_owner_scope() rebinds the auth identity to owner_id
while keeping default_sender_id as the gateway user_id. This caused
a FK constraint violation when creating users because the auth
identity ("default") didn't match any user in the DB ("nearai").

Changes:
- Remove GATEWAY_USER_ID env var and gateway_user_id from settings
- Remove user_id field from GatewayConfig
- Add owner_id parameter to GatewayChannel::new()
- Remove with_owner_scope() method
- Remove default_sender_id from GatewayState
- Remove sender override logic in chat/approval handlers
- Remove debug endpoint and tracing from prior debugging
- Update all tests and E2E fixtures

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

src/channels/web/mod.rs

@@ -73,7 +73,7 @@ impl GatewayChannel {
     ///
     /// If no auth token is configured, generates a random one and prints it.
     /// Builds a single-user `MultiAuthState` from the config.
-    pub fn new(config: GatewayConfig) -> Self {
+    pub fn new(config: GatewayConfig, owner_id: String) -> Self {
         let auth_token = config.auth_token.clone().unwrap_or_else(|| {
             use rand::RngCore;
             use rand::rngs::OsRng;
@@ -83,7 +83,7 @@ impl GatewayChannel {
         });
 
         let auth = CombinedAuthState {
-            env_auth: MultiAuthState::single(auth_token, config.user_id.clone()),
+            env_auth: MultiAuthState::single(auth_token, owner_id.clone()),
             db_auth: None,
         };
 
@@ -101,8 +101,7 @@ impl GatewayChannel {
             job_manager: None,
             prompt_queue: None,
             scheduler: None,
-            owner_id: config.user_id.clone(),
-            default_sender_id: config.user_id.clone(),
+            owner_id,
             shutdown_tx: tokio::sync::RwLock::new(None),
             ws_tracker: Some(Arc::new(ws::WsConnectionTracker::new())),
             llm_provider: None,
@@ -126,18 +125,6 @@ impl GatewayChannel {
         }
     }
 
-    /// Rebind the single-user auth identity to the durable owner scope while
-    /// preserving the configured gateway sender/routing identity.
-    pub fn with_owner_scope(mut self, owner_id: impl Into<String>) -> Self {
-        let owner_id = owner_id.into();
-        let single_user_token = self.auth.env_auth.first_token().map(ToOwned::to_owned);
-        if let Some(token) = single_user_token {
-            self.auth.env_auth = MultiAuthState::single(token, owner_id.clone());
-        }
-        self.rebuild_state(|s| s.owner_id = owner_id);
-        self
-    }
-
     /// Helper to rebuild state, copying existing fields and applying a mutation.
     fn rebuild_state(&mut self, mutate: impl FnOnce(&mut GatewayState)) {
         let mut new_state = GatewayState {
@@ -156,7 +143,6 @@ impl GatewayChannel {
             prompt_queue: self.state.prompt_queue.clone(),
             scheduler: self.state.scheduler.clone(),
             owner_id: self.state.owner_id.clone(),
-            default_sender_id: self.state.default_sender_id.clone(),
             shutdown_tx: tokio::sync::RwLock::new(None),
             ws_tracker: self.state.ws_tracker.clone(),
             llm_provider: self.state.llm_provider.clone(),