feat(phase10): complete MCP-only architecture migration

Phase 10 "Cleanup & Production Polish" is now complete. All LLM
interactions now go through the Model Context Protocol (MCP), removing
direct provider dependencies from CLI/TUI.

## Major Changes

### MCP Architecture
- All providers (local and cloud Ollama) now use RemoteMcpClient
- Removed owlen-ollama dependency from owlen-tui
- MCP LLM server accepts OLLAMA_URL environment variable for cloud providers
- Proper notification handling for streaming responses
- Fixed response deserialization (McpToolResponse unwrapping)

### Code Cleanup
- Removed direct OllamaProvider instantiation from TUI
- Updated collect_models_from_all_providers() to use MCP for all providers
- Updated switch_provider() to use MCP with environment configuration
- Removed unused general config variable

### Documentation
- Added comprehensive MCP Architecture section to docs/architecture.md
- Documented MCP communication flow and cloud provider support
- Updated crate breakdown to reflect MCP servers

### Security & Performance
- Path traversal protection verified for all resource operations
- Process isolation via separate MCP server processes
- Tool permissions controlled via consent manager
- Clean release build of entire workspace verified

## Benefits of MCP Architecture

1. **Separation of Concerns**: TUI/CLI never directly instantiates providers
2. **Process Isolation**: LLM interactions run in separate processes
3. **Extensibility**: New providers can be added as MCP servers
4. **Multi-Transport**: Supports STDIO, HTTP, and WebSocket
5. **Tool Integration**: MCP servers expose tools to LLMs

This completes Phase 10 and establishes a clean, production-ready architecture
for future development.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

crates/owlen-mcp-llm-server/src/lib.rs

@@ -107,8 +107,10 @@ fn resources_list_descriptor() -> McpToolDescriptor {
 }
 
 async fn handle_generate_text(args: GenerateTextArgs) -> Result<String, RpcError> {
-    // Create provider with default local Ollama URL
-    let provider = OllamaProvider::new("http://localhost:11434")
+    // Create provider with Ollama URL from environment or default to localhost
+    let ollama_url =
+        env::var("OLLAMA_URL").unwrap_or_else(|_| "http://localhost:11434".to_string());
+    let provider = OllamaProvider::new(&ollama_url)
         .map_err(|e| RpcError::internal_error(format!("Failed to init OllamaProvider: {}", e)))?;
 
     let parameters = ChatParameters {
@@ -190,7 +192,9 @@ async fn handle_request(req: &RpcRequest) -> Result<Value, RpcError> {
         // New method to list available Ollama models via the provider.
         methods::MODELS_LIST => {
             // Reuse the provider instance for model listing.
-            let provider = OllamaProvider::new("http://localhost:11434").map_err(|e| {
+            let ollama_url =
+                env::var("OLLAMA_URL").unwrap_or_else(|_| "http://localhost:11434".to_string());
+            let provider = OllamaProvider::new(&ollama_url).map_err(|e| {
                 RpcError::internal_error(format!("Failed to init OllamaProvider: {}", e))
             })?;
             let models = provider
@@ -377,7 +381,9 @@ async fn main() -> anyhow::Result<()> {
                         };
 
                     // Initialize Ollama provider and start streaming
-                    let provider = match OllamaProvider::new("http://localhost:11434") {
+                    let ollama_url = env::var("OLLAMA_URL")
+                        .unwrap_or_else(|_| "http://localhost:11434".to_string());
+                    let provider = match OllamaProvider::new(&ollama_url) {
                         Ok(p) => p,
                         Err(e) => {
                             let err_resp = RpcErrorResponse::new(