feat(mcp): enforce spec-compliant tool registry

- Reject dotted tool identifiers during registration and remove alias-backed lookups.
- Drop web.search compatibility, normalize all code/tests around the canonical web_search name, and update consent/session logic.
- Harden CLI toggles to manage the spec-compliant identifier and ensure MCP configs shed non-compliant entries automatically.

Acceptance Criteria:
- Tool registry denies invalid identifiers by default and no alias codepaths remain.

Test Notes:
- cargo check -p owlen-core (tests unavailable in sandbox).

crates/owlen-core/src/session.rs

@@ -19,6 +19,7 @@ use crate::model::{DetailedModelInfo, ModelManager};
 use crate::oauth::{DeviceAuthorization, DevicePollState, OAuthClient};
 use crate::providers::OllamaProvider;
 use crate::storage::{SessionMeta, StorageManager};
+use crate::tools::{WEB_SEARCH_TOOL_NAME, canonical_tool_name, tool_name_matches};
 use crate::types::{
     ChatParameters, ChatRequest, ChatResponse, Conversation, Message, ModelInfo, ToolCall,
 };
@@ -407,7 +408,7 @@ async fn build_tools(
         .security
         .allowed_tools
         .iter()
-        .any(|tool| tool == "web_search")
+        .any(|tool| tool_name_matches(tool, WEB_SEARCH_TOOL_NAME))
         && config_guard.tools.web_search.enabled
         && config_guard.privacy.enable_remote_search
     {
@@ -424,7 +425,7 @@ async fn build_tools(
 
     if let Some(settings) = web_search_settings {
         let tool = WebSearchTool::new(consent_manager.clone(), settings);
-        registry.register(tool);
+        registry.register(tool)?;
     }
 
     // Register web_scrape tool if allowed.
@@ -432,12 +433,12 @@ async fn build_tools(
         .security
         .allowed_tools
         .iter()
-        .any(|tool| tool == "web_scrape")
+        .any(|tool| tool_name_matches(tool, "web_scrape"))
         && config_guard.tools.web_search.enabled // reuse web_search toggle for simplicity
         && config_guard.privacy.enable_remote_search
     {
         let tool = WebScrapeTool::new();
-        registry.register(tool);
+        registry.register(tool)?;
     }
 
     if enable_code_tools
@@ -449,11 +450,11 @@ async fn build_tools(
         && config_guard.tools.code_exec.enabled
     {
         let tool = CodeExecTool::new(config_guard.tools.code_exec.allowed_languages.clone());
-        registry.register(tool);
+        registry.register(tool)?;
     }
 
-    registry.register(ResourcesListTool);
-    registry.register(ResourcesGetTool);
+    registry.register(ResourcesListTool)?;
+    registry.register(ResourcesGetTool)?;
 
     if config_guard
         .security
@@ -461,7 +462,7 @@ async fn build_tools(
         .iter()
         .any(|t| t == "file_write")
     {
-        registry.register(ResourcesWriteTool);
+        registry.register(ResourcesWriteTool)?;
     }
     if config_guard
         .security
@@ -469,7 +470,7 @@ async fn build_tools(
         .iter()
         .any(|t| t == "file_delete")
     {
-        registry.register(ResourcesDeleteTool);
+        registry.register(ResourcesDeleteTool)?;
     }
 
     for tool in registry.all() {
@@ -1023,13 +1024,14 @@ impl SessionController {
         let mut seen_tools = std::collections::HashSet::new();
 
         for tool_call in tool_calls {
-            if seen_tools.contains(&tool_call.name) {
+            let canonical = canonical_tool_name(tool_call.name.as_str()).to_string();
+            if seen_tools.contains(&canonical) {
                 continue;
             }
-            seen_tools.insert(tool_call.name.clone());
+            seen_tools.insert(canonical.clone());
 
-            let (data_types, endpoints) = match tool_call.name.as_str() {
-                "web_search" => (
+            let (data_types, endpoints) = match canonical.as_str() {
+                WEB_SEARCH_TOOL_NAME => (
                     vec!["search query".to_string()],
                     vec!["cloud provider".to_string()],
                 ),
@@ -1097,13 +1099,14 @@ impl SessionController {
     pub async fn set_tool_enabled(&mut self, tool: &str, enabled: bool) -> Result<()> {
         {
             let mut config = self.config.lock().await;
-            match tool {
-                "web_search" => {
+            let canonical = canonical_tool_name(tool);
+            match canonical {
+                WEB_SEARCH_TOOL_NAME => {
                     config.tools.web_search.enabled = enabled;
                     config.privacy.enable_remote_search = enabled;
                 }
                 "code_exec" => config.tools.code_exec.enabled = enabled,
-                other => return Err(Error::InvalidInput(format!("Unknown tool: {other}"))),
+                _ => return Err(Error::InvalidInput(format!("Unknown tool: {tool}"))),
             }
         }
         self.rebuild_tools().await
@@ -1897,12 +1900,12 @@ mod tests {
     #[test]
     fn streaming_state_detects_tool_call_changes() {
         let mut state = StreamingMessageState::new();
-        let tool = make_tool_call("call-1", "web.search");
+        let tool = make_tool_call("call-1", "web_search");
 
         let diff = state.ingest(&make_response("", Some(vec![tool.clone()]), false));
         let calls = diff.tool_calls.expect("initial tool call");
         assert_eq!(calls.len(), 1);
-        assert_eq!(calls[0].name, "web.search");
+        assert_eq!(calls[0].name, "web_search");
 
         let diff = state.ingest(&make_response("", Some(vec![tool.clone()]), false));
         assert!(