IB-WP-0019-T05: state-hub token-event emission with failure isolation

Emit one record_token_event payload per completed generate run, derived
from the just-recorded usage rollup. tokens_in/out come from the
rollup, model defaults to the dominant model used (or "mixed" when
buckets disagree), agent="infospace-bench", ref_type="session", and
ref_id="<slug>/run-<run_index>". The note carries the infospace slug,
workspace, snapshot_id, and any known/estimated cost so the hub event
is self-describing.

Failure isolation: any exception from the HTTP poster (hub down,
timeout, 5xx) is caught, logged to stderr, and reported as
status=failed; the generate run still completes. INFOSPACE_BENCH_HUB_URL
overrides the default http://127.0.0.1:8000 base;
INFOSPACE_BENCH_DISABLE_HUB_TOKEN_EVENTS skips emission entirely.

Tests cover the happy path, the disable env var, poster failure, the
no-usage skip, multi-model coalescing to "mixed", and an end-to-end
run_generation against an unbindable hub port to prove the run survives
when the hub is unreachable. 116 tests pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/infospace_bench/generator.py

@@ -19,6 +19,7 @@ from .history import get_history, read_metrics_file, record_check_results
 from .lifecycle import create_infospace, load_infospace, register_artifact
 from .openrouter import OpenRouterAssistedGenerationAdapter
 from .budget import (
+    emit_token_event,
     latest_plan_snapshot_id,
     make_cost_resolver,
     read_run_variance,
@@ -411,6 +412,11 @@ def run_generation(
             cost_resolver=make_cost_resolver(_workspace_for(root_path)),
         )
         record_run_variance(root_path, usage_entry)
+        emit_token_event(
+            usage_entry,
+            infospace_slug=load_infospace(root_path).config.slug,
+            workspace=str(_workspace_for(root_path)),
+        )
 
     metrics: dict[str, Any] = {}
     snapshot_id = ""