feat: implement project launch script run.sh and update README

specs/003-project-launch-script/spec.md

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+# Feature Specification: Project Launch Script
+
+**Feature Branch**: `003-project-launch-script`
+**Created**: 2025-12-20
+**Status**: Draft
+**Input**: User description: "давай создадим скрипт для запуска проекта"
+
+## User Scenarios & Testing *(mandatory)*
+
+### User Story 1 - Launch Project (Priority: P1)
+
+As a developer, I want to launch the entire project (backend and frontend) with a single command so that I can start working quickly without manually running multiple commands in different terminals.
+
+**Why this priority**: This is the core functionality requested. It simplifies the development workflow.
+
+**Independent Test**: Can be fully tested by running the script and verifying that both backend and frontend services are accessible.
+
+**Acceptance Scenarios**:
+
+1. **Given** the project is cloned and I am in the root directory, **When** I run the launch script, **Then** the script checks for dependencies, installs them if missing, and starts both backend and frontend servers.
+2. **Given** the servers are running, **When** I press Ctrl+C, **Then** both backend and frontend processes terminate gracefully.
+3. **Given** dependencies are missing, **When** I run the script, **Then** it installs them before starting the servers.
+
+---
+
+### Edge Cases
+
+- What happens when a port is already in use? The underlying tools (uvicorn/vite) will likely fail or complain. The script should ideally show this output.
+- What happens if `python3` or `npm` is missing? The script should fail with a clear error message.
+
+## Requirements *(mandatory)*
+
+### Functional Requirements
+
+- **FR-001**: The script MUST be executable from the project root (e.g., `./run.sh`).
+- **FR-002**: The script MUST check if `python3` and `npm` are available in the environment.
+- **FR-003**: The script MUST check for and install backend dependencies from `backend/requirements.txt` if they are missing or outdated.
+- **FR-004**: The script MUST check for and install frontend dependencies from `frontend/package.json` if `node_modules` is missing.
+- **FR-005**: The script MUST start the backend application server in development mode.
+- **FR-006**: The script MUST start the frontend application server in development mode.
+- **FR-007**: The script MUST run both backend and frontend processes concurrently.
+- **FR-008**: The script MUST handle `SIGINT` (Ctrl+C) to terminate both processes gracefully.
+
+### Key Entities *(include if feature involves data)*
+
+N/A
+
+## Success Criteria *(mandatory)*
+
+### Measurable Outcomes
+
+- **SC-001**: Developers can start the full stack with 1 command.
+- **SC-002**: Both backend and frontend services are accessible via their configured network ports within 30 seconds of running the script (assuming dependencies are installed).
+- **SC-003**: 100% of child processes are terminated when the script is stopped.