The endpoint was a contract-phase stub returning `[]` even though the
RuleStore loaded all 58 YAML rules at worker startup. UI saw an empty
table; operators couldn't tell whether anything was wired up.
- `api_list_rules` now calls `get_rule_store().load_compiled()` and
serializes each CompiledRule + its operational state into a
RuleCatalogueRow. Sorted by rule_id for stable golden snapshots.
- Add `description: str` to RuleSchema (pydantic) and CompiledRule
(NamedTuple, defaulted) + propagate through `_compile_one` so the
catalogue surfaces the human-readable YAML description, not just
the slug-style `name`.
- Update `tests/ttp/test_rule_engine.py` _fields assertion for the
new column; new `tests/api/ttp/test_rules_catalogue.py` pins the
catalogue contents (R0001/R0014 presence, row shape, sort order).
Worker behaviour is unchanged: it was already loading rules
correctly. This is purely a read-side wiring fix on the operator API.