**Problem:**
The telemetry system had unnecessary abstraction layers and bad practices
from the last 3 commits introducing the gateway implementation:
- TelemetryFacade class wrapper around emit() function
- String literals instead of SignalType enum
- Dictionary mapping enum → string instead of enum → enum
- Unnecessary ENTERPRISE_TELEMETRY_GATEWAY_ENABLED feature flag
- Duplicate guard checks scattered across files
- Non-thread-safe TelemetryGateway singleton pattern
- Missing guard in ops_trace_task.py causing RuntimeError spam
**Solution:**
1. Deleted TelemetryFacade - replaced with thin emit() function in core/telemetry/__init__.py
2. Added SignalType enum ('trace' | 'metric_log') to enterprise/telemetry/contracts.py
3. Replaced CASE_TO_TRACE_TASK_NAME dict with CASE_TO_TRACE_TASK: dict[TelemetryCase, TraceTaskName]
4. Deleted is_gateway_enabled() and _emit_legacy() - using existing ENTERPRISE_ENABLED + ENTERPRISE_TELEMETRY_ENABLED instead
5. Extracted _should_drop_ee_only_event() helper to eliminate duplicate checks
6. Moved TelemetryGateway singleton to ext_enterprise_telemetry.py:
- Init once in init_app() for thread-safety
- Access via get_gateway() function
7. Re-added guard to ops_trace_task.py to prevent RuntimeError when EE=OFF but CE tracing enabled
8. Updated 11 caller files to import 'emit as telemetry_emit' instead of 'TelemetryFacade'
**Result:**
- 322 net lines deleted (533 removed, 211 added)
- All 91 tests pass
- Thread-safe singleton pattern
- Cleaner API surface: from TelemetryFacade.emit() to telemetry_emit()
- Proper enum usage throughout
- No RuntimeError spam in EE=OFF + CE=ON scenario
Changes:
- Change TelemetryEvent.name from str to TraceTaskName enum for type safety
- Remove hardcoded trace_task_name_map from facade (no mapping needed)
- Add centralized enterprise-only filter in TelemetryFacade.emit()
- Rename is_telemetry_enabled() to is_enterprise_telemetry_enabled()
- Update all 11 call sites to pass TraceTaskName enum values
- Remove redundant enterprise guard from draft_trace.py
- Add unit tests for TelemetryFacade.emit() routing (6 tests)
- Add unit tests for TraceQueueManager telemetry guard (5 tests)
- Fix test fixture scoping issue for full test suite compatibility
- Fix tenant_id handling in agent tool callback handler
Benefits:
- 100% type-safe: basedpyright catches errors at compile time
- No string literals: eliminates entire class of typo bugs
- Single point of control: centralized filtering in facade
- All guards removed except facade
- Zero regressions: 4887 tests passing
Verification:
- make lint: PASS
- make type-check: PASS (0 errors, 0 warnings)
- pytest: 4887 passed, 8 skipped
Migrate from direct TraceQueueManager.add_trace_task calls to TelemetryFacade.emit
with TelemetryEvent abstraction. This reduces CE code invasion by consolidating
telemetry logic in core/telemetry/ with a single guard in ops_trace_manager.py.
GareArc