IB-WP-0020-T04: example routing config + live routing smoke

examples/routing/trading-literature.yaml is the checked-in starting
config for a Lefevre-style run. It applies the IB-WP-0018 task-type
taxonomy: cheap candidates for summary + evaluation, smart candidates
for entity + relation extraction, and a separate baseline rule wiring
claude_code for a follow-on T05 ShadowingAdapter step. Workspace-
relative ledger_path keeps adaptive observations with the workspace.

tests/test_routing_config.py gains a regression test that asserts the
shipped example parses cleanly, every stage in stage_to_task_type maps
to a declared task type, and the baseline candidate uses the
claude_code provider — so the example will not bit-rot silently.

tests/test_openrouter_live.py gains test_provider_routing_one_chapter_live_smoke
gated on the same INFOSPACE_BENCH_ENABLE_LIVE_OPENROUTER + OPENROUTER_API_KEY
opt-in as the existing static smoke. It builds a one-candidate routing
config, runs a single chapter through --provider routing, and asserts
the per-stage adapter-choices report section names the routed model
and the routed artifacts carry adapter_id provenance.

docs/generic-source-generator.md gains a "Live runs with --provider
routing" subsection that walks through the one-command routed run,
explains the --quality-floor override, and points at the parallel
live smoke test.

174 tests pass, 2 skipped (both live smokes, correctly gated).

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

workplans/IB-WP-0020-provider-routing-cli.md

@@ -138,7 +138,7 @@ state_hub_task_id: "fe5888e0-da33-413a-b026-71ed811b8c73"
 
 ```task
 id: IB-WP-0020-T04
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "69288131-f265-4db5-a4b0-b0c8a6f55dd8"
 ```