feat(WP-0003c): context adapters, first ActivityDefinition, full test suite

T51: ContextResolver ABC + CONTEXT_RESOLVER_REGISTRY; resolve_context activity
updated to dispatch via registry (warns + binds {} on failure, never aborts run).
T52: RepoScopingContextResolver with 5-min in-process cache.
T53: StateHubContextResolver (no cache) for domain_summary and repo_sbom_status.
T54: activity-definitions/weekly-sbom-staleness.md (Monday 09:00 Berlin, cron
trigger, flag-stale-sbom rule at >30 days) + tasks/sbom-rescan.md template.
T55: 51 parametrized evaluator tests — all whitelisted operators, unsafe
expression rejection, empty condition, missing attribute, nested context access.
T56: 15 executor safety tests — UntrustedFieldError, object-type rejection,
injection fixture, LLM retry on bad JSON, review_required field.
T57: 6 integration tests — parses real definition, evaluates rule per-repo
(stale/fresh boundary), emits via NullSink, verifies spawn log entries.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/activity_core/workflows.py

@@ -95,7 +95,7 @@ class RunActivityWorkflow:
         # ── 2. Resolve context ────────────────────────────────────────────────
         context_snapshot: dict = await workflow.execute_activity(
             resolve_context,
-            defn["context_sources"],
+            args=[defn["context_sources"], event_envelope_json],
             start_to_close_timeout=_ACTIVITY_TIMEOUT,
             retry_policy=_RETRY_POLICY,
         )