docs(src): Update documentation for src/ layout and sloppy.py entry point

docs/guide_architecture.md

@@ -8,6 +8,28 @@
 
 Manual Slop solves a single tension: **AI reasoning is high-latency and non-deterministic; GUI interaction must be low-latency and responsive.** The engine enforces strict decoupling between three thread domains so that multi-second LLM calls never block the render loop, and every AI-generated payload passes through a human-auditable gate before execution.
 
+## Project Structure
+
+The codebase is organized into a `src/` layout to separate implementation from configuration and artifacts.
+
+```
+manual_slop/
+├── conductor/          # Conductor tracks, specs, and plans
+├── docs/               # Deep-dive architectural documentation
+├── logs/               # Session logs, agent traces, and errors
+├── scripts/            # Build, migration, and IPC bridge scripts
+├── src/                # Core Python implementation
+│   ├── ai_client.py    # LLM provider abstraction
+│   ├── gui_2.py        # Main ImGui application
+│   ├── mcp_client.py   # MCP tool implementation
+│   └── ...             # Other core modules
+├── tests/              # Pytest suite and simulation fixtures
+├── simulation/         # Workflow and agent simulation logic
+├── sloppy.py           # Primary application entry point
+├── config.toml         # Global application settings
+└── manual_slop.toml    # Project-specific configuration
+```
+
 ---
 
 ## Thread Domains