standalone: add MCP client + tool-call loop

- Add mcp/McpConfig + McpRegistry wrapping io.modelcontextprotocol:kotlin-sdk-client 0.15.0
  - Supports stdio (uvx/npx/python) and streamable HTTP transports
  - Claude Desktop-compatible JSON config (AGENTIK_MCP_CONFIG)
  - server__tool name prefix to avoid collisions between servers
- Add agent/NamedTool (name + LiteTool pair) and tools: List<NamedTool> on ChatAgent/ChatConversation
- Implement tool-call loop in ChatConversation.runTurn:
  - delta.toolCalls -> emit ToolCall event -> persist audit -> execute tool
    -> emit ToolResult -> persist -> liteConv.addToolResult(callId, name, result)
  - separate tc-/tr- prefixes keep SQL PRIMARY KEY unique while toolCallId FK is preserved
- 8 McpConfig + 4 McpRegistry unit tests; +1 ChatAgentTest tool-loop test (44/44 total)
- e2e verified: real MCP fetch server (mcp-server-fetch) + litellm local/codding
  -> LLM calls fetch__fetch, MCP exec, result fed back, conversation continues

docs/STANDALONE.md: drop 'no tools / no MCP' from §8; replace 'Подключить тул (v2)' stub
with full in-agent + MCP recipe and tool-loop algorithm in §7

gradle/libs.versions.toml

@@ -46,6 +46,10 @@ ktor-client-core = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 ktor-client-cio = { module = "io.ktor:ktor-client-cio", version.ref = "ktor" }
 ktor-client-content-negotiation = { module = "io.ktor:ktor-client-content-negotiation", version.ref = "ktor" }
 ktor-server-test-host = { module = "io.ktor:ktor-server-test-host", version.ref = "ktor" }
+ktor-client-sse = { module = "io.ktor:ktor-client-sse", version.ref = "ktor" }
+
+# --- Model Context Protocol (MCP) ---
+mcp-sdk-client = { module = "io.modelcontextprotocol:kotlin-sdk-client", version = "0.15.0" }
 
 kotlin-test = { module = "org.jetbrains.kotlin:kotlin-test", version.ref = "kotlin" }