fix: use available bounded research search provider

dev/ACTIVE_TASK.json

@@ -1,5 +1,5 @@
 {
-  "task_file": "dev/tasks/DEV-000275-semantic-web-research-routing.json",
-  "task_id": "DEV-000275",
+  "task_file": "dev/tasks/DEV-000276-research-search-provider-fallback.json",
+  "task_id": "DEV-000276",
   "task_revision": 1
 }

dev/tasks/DEV-000276-research-search-provider-fallback.json

@@ -0,0 +1,23 @@
+{
+  "task_id": "DEV-000276",
+  "task_revision": 1,
+  "architecture_revision": "ADR-0018",
+  "base_repo_revision": "c09be4c",
+  "risk_tier": "E",
+  "intent": "Replace the blocked default search provider with an available configured HTML search endpoint while preserving bounded parsing and truth-first failure behavior.",
+  "requirement_ids": ["research provider fallback", "no fabricated evidence", "optional external channel"],
+  "allowed_change_scope": {"modules": ["research-runtime", "deployment"], "paths": ["adapters/research/search_connector.go", "deploy/docker-compose.prod.yml", "tests/research_runtime/search_connector_test.go", "dev/ACTIVE_TASK.json", "dev/tasks/DEV-000276-research-search-provider-fallback.json", "docs/PROJECT_STATUS.md", "docs/evidence/**"]},
+  "forbidden_change_scope": {"paths": ["architecture/**", "security/**", "database/**", "contracts/**", "LLM-local/**"]},
+  "allowed_architecture_delta": {"new_cross_module_dependencies": 0, "new_canonical_owners": 0, "new_privileges": 1, "new_third_party_dependencies": 0, "new_database_owner_roles": 0},
+  "contracts": {"consume": ["existing WebSearchRequest and evidence chain"], "may_change": ["bounded provider response parsing"]},
+  "semantic_owner": "research runtime owns source collection and evidence preservation",
+  "canonical_state": ["existing epistemics source snapshot and citation chain"],
+  "state_transitions": ["configured provider response -> bounded excerpts", "provider challenge/no result -> unknown evidence"],
+  "side_effects_and_privileges": ["read-only HTTPS fetch to operator allowlist"],
+  "persistence_and_migrations": ["none"],
+  "failure_retry_restart": ["provider failure never becomes a supported finding"],
+  "assumptions": ["operator may override search URL and host allowlist", "search results are source excerpts, not generated answers"],
+  "acceptance_scenarios": ["Bing-style bounded result is collected", "unallowlisted endpoint is rejected", "provider challenge yields no evidence", "no entity-specific query logic exists"],
+  "required_tests": ["go test ./...", "go vet ./...", "preflight", "check-diff", "check-architecture", "independent", "git diff --check", "CI", "production research-runtime smoke"],
+  "terminal_gap_states": ["BLOCKED_BY_MISSING_CAPABILITY"]
+}