Declarative event_log and pipeline monitoring support

[Mmodarre]

Summary

Add declarative event_log and monitoring configuration support to LHP, enabling automatic event log table creation and cross-pipeline monitoring through lhp.yaml project-level settings.

Features

Event Log Configuration (lhp.yaml)

• New event_log: section in lhp.yaml for project-wide event log configuration
• Supports catalog, schema, and name_suffix fields with LHP token substitution
• Automatically injects event_log block into generated bundle resource YAML for all pipelines
• Pipeline-level override: define event_log: in pipeline_config.yaml to fully replace the project setting
• Pipeline-level opt-out: set event_log: false in pipeline_config.yaml to disable for a specific pipeline

Monitoring Pipeline

• New monitoring: section in lhp.yaml to generate a synthetic monitoring pipeline
• Automatically UNIONs all pipeline event log tables into a streaming table with materialized views
• Configurable: pipeline_name, catalog, schema, streaming_table, materialized_views
• Support for __eventlog_monitoring alias in pipeline_config.yaml for monitoring pipeline settings
• Custom materialized views with user-defined SQL or file-based SQL paths

Bundle Resource Generation

• Template renders event_log: block with name, schema, catalog fields
• Monitoring pipeline generates its own bundle resource file
• lhp generate creates monitoring flowgroup Python code alongside regular pipelines

Tests

• Integration and unit tests for monitoring configuration and event log
• E2E tests with baselines for event log injection, override, disable, and monitoring variants