Initial commit: scheduler service extraction from portainer-core

Extracted standalone scheduler service with:
- FastAPI REST API for task management
- APScheduler-based task execution
- PostgreSQL persistence
- Docker container support
- Gitea Actions CI/CD workflow

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/test_database_setup.sql

@@ -0,0 +1,106 @@
+-- Test Database Setup for Scheduler Tests
+-- Creates a dedicated test database with the same schema as production
+
+-- Create test database and user (run as postgres superuser)
+CREATE DATABASE test_scheduler;
+CREATE USER test_scheduler_user WITH PASSWORD 'test_password_12345';
+GRANT ALL PRIVILEGES ON DATABASE test_scheduler TO test_scheduler_user;
+
+-- Connect to test database
+\c test_scheduler
+
+-- Grant schema permissions
+GRANT ALL ON SCHEMA public TO test_scheduler_user;
+
+-- Create scheduled_tasks table (same as production)
+CREATE TABLE scheduled_tasks (
+    id SERIAL PRIMARY KEY,
+    task_name VARCHAR(100) NOT NULL UNIQUE,
+    service VARCHAR(50) NOT NULL,
+    executor VARCHAR(100) NOT NULL,
+    priority INTEGER NOT NULL DEFAULT 30,
+
+    -- Scheduling (supports wildcards: -1 = any)
+    minute INTEGER DEFAULT -1,
+    hour INTEGER DEFAULT -1,
+    day_of_month INTEGER DEFAULT -1,
+    month INTEGER DEFAULT -1,
+    day_of_week INTEGER DEFAULT -1,
+
+    enabled BOOLEAN DEFAULT true,
+    description TEXT,
+    config JSONB,
+
+    -- Execution tracking
+    last_run TIMESTAMP,
+    last_status VARCHAR(20),
+    last_duration_seconds INTEGER,
+    retry_count INTEGER DEFAULT 0,
+    max_retries INTEGER DEFAULT 3,
+    timeout_seconds INTEGER DEFAULT 3600,
+
+    -- Metadata
+    created_at TIMESTAMP DEFAULT NOW(),
+    updated_at TIMESTAMP DEFAULT NOW(),
+    created_by VARCHAR(50),
+
+    -- Constraints
+    CHECK (priority >= 1 AND priority <= 100),
+    CHECK (minute >= -1 AND minute <= 59),
+    CHECK (hour >= -1 AND hour <= 23),
+    CHECK (day_of_month >= -1 AND day_of_month <= 31),
+    CHECK (month >= -1 AND month <= 12),
+    CHECK (day_of_week >= -1 AND day_of_week <= 6)
+);
+
+-- Create task_executions table (same as production)
+CREATE TABLE task_executions (
+    id SERIAL PRIMARY KEY,
+    task_id INTEGER NOT NULL REFERENCES scheduled_tasks(id),
+    task_name VARCHAR(100) NOT NULL,
+    service VARCHAR(50) NOT NULL,
+    executor VARCHAR(100) NOT NULL,
+    priority INTEGER NOT NULL,
+
+    status VARCHAR(20) NOT NULL,
+    triggered_by VARCHAR(50),
+    triggered_at TIMESTAMP DEFAULT NOW(),
+    started_at TIMESTAMP,
+    completed_at TIMESTAMP,
+    duration_seconds INTEGER,
+
+    output TEXT,
+    error TEXT,
+    retry_count INTEGER DEFAULT 0,
+    metadata JSONB
+);
+
+-- Create indexes
+CREATE INDEX idx_tasks_enabled ON scheduled_tasks(enabled) WHERE enabled = true;
+CREATE INDEX idx_tasks_priority ON scheduled_tasks(priority);
+CREATE INDEX idx_tasks_service ON scheduled_tasks(service);
+CREATE INDEX idx_tasks_schedule ON scheduled_tasks(minute, hour, day_of_month, month, day_of_week) WHERE enabled = true;
+
+CREATE INDEX idx_executions_task_id ON task_executions(task_id);
+CREATE INDEX idx_executions_task_name ON task_executions(task_name);
+CREATE INDEX idx_executions_status ON task_executions(status);
+CREATE INDEX idx_executions_triggered_at ON task_executions(triggered_at DESC);
+CREATE INDEX idx_executions_service ON task_executions(service);
+CREATE INDEX idx_executions_running ON task_executions(task_id) WHERE status = 'running';
+
+-- Grant permissions
+GRANT ALL ON ALL TABLES IN SCHEMA public TO test_scheduler_user;
+GRANT ALL ON ALL SEQUENCES IN SCHEMA public TO test_scheduler_user;
+
+-- Insert test data
+INSERT INTO scheduled_tasks
+    (task_name, service, executor, priority, minute, hour, description, config, created_by)
+VALUES
+    ('test_fixture_task', 'scheduler', 'example_executor', 50, -1, -1,
+     'Test fixture task for integration tests',
+     '{"message": "Test fixture", "delay_seconds": 0}'::jsonb,
+     'test_setup');
+
+-- Verify
+SELECT COUNT(*) as task_count FROM scheduled_tasks;
+SELECT COUNT(*) as execution_count FROM task_executions;