Note: the web dashboard has been rebuilt in React 19 + shadcn/ui as part of #762. Vue/PrimeVue references in this issue are outdated.

Summary

The observability module supports a comprehensive 7+1 sink layout (console + synthorg.log + audit.log + errors.log + agent_activity.log + cost_usage.log + debug.log + access.log) with per-sink levels, JSON/text formatting, rotation, and logger name routing. Currently, sink configuration is static -- baked into DEFAULT_SINKS at startup. The SettingsService observability namespace only has 2 settings (root_log_level, enable_correlation).

This issue expands the observability namespace to support full runtime sink CRUD via the REST API and settings UI.

Scope

• Add settings definitions for sink configuration in settings/definitions/observability.py:
  • Per-sink enable/disable toggle
  • Per-sink log level override
  • Per-sink JSON format toggle
  • Rotation config (max_bytes, backup_count, strategy)
  • Custom sink creation (file path, level, logger name routing)
• Settings subscriber: ObservabilitySettingsSubscriber that reconfigures the logging pipeline when sink settings change (via configure_logging() re-invocation -- it's already idempotent)
• API exposure: Settings schema endpoints already support auto-discovery for dynamic UI generation -- ensure observability namespace sinks render correctly in the settings page
• Validation: Prevent removal of the console sink (always need at least one output). Validate file paths (no traversal, relative only). Validate logger name prefixes.
• Hot reload safety: Log pipeline reconfiguration must not drop messages. Use the existing _clear_root_handlers + re-attach pattern in configure_logging().

Dependencies

• Logging bootstrap wiring (activate the sink system first)

Acceptance Criteria

• Each default sink can be enabled/disabled at runtime via settings API
• Per-sink log level can be changed at runtime
• Changes take effect without restart (settings subscriber triggers reconfiguration)
• At least one sink must remain active (validation)
• Settings page auto-discovers and renders sink configuration
• Custom sinks can be added via settings (file path + level + routing)
• Tests cover hot reload, validation, and subscriber integration