chore: Bump version to 0.1.3

- Fix: Skip empty/whitespace-only text content blocks in chat completions
- This resolves Anthropic API errors:
  - "messages: text content blocks must contain non-whitespace text"
  - "messages: text content blocks must be non-empty"
- Updated version strings in all test files and snapshots

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

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

llmx-rs/mcp-server/tests/common/mcp_process.rs

@@ -144,7 +144,7 @@ impl McpProcess {
         let initialized = self.read_jsonrpc_message().await?;
         let os_info = os_info::get();
         let user_agent = format!(
-            "llmx_cli_rs/0.1.2 ({} {}; {}) {} (elicitation test; 0.0.0)",
+            "llmx_cli_rs/0.1.3 ({} {}; {}) {} (elicitation test; 0.0.0)",
             os_info.os_type(),
             os_info.version(),
             os_info.architecture().unwrap_or("unknown"),
@@ -163,7 +163,7 @@ impl McpProcess {
                     "serverInfo": {
                         "name": "llmx-mcp-server",
                         "title": "LLMX",
-                        "version": "0.1.2",
+                        "version": "0.1.3",
                         "user_agent": user_agent
                     },
                     "protocolVersion": mcp_types::MCP_SCHEMA_VERSION