Merge task/449 into the risk-tier fix branch (V-523)

Brings internal/tool/risk.go in so the Hexis split can be written against it.
Four conflicts, all additive: both grammar sets in voicewire.go, both test
sets in agenda_test.go and stage0.go, and in actions_act.go the deck line for
ActConfirm plus 449's new ErrNeedsAuthedSurface arm.

Two renames the merge forced. actions_list_test.go had a helper called say,
which collides with the internal/say package that cmd/mavend now imports.
actions_act_risk_test.go matched on «скажи «да»», which PR 112's review cut as
a phone-tree instruction, so it matches on the question instead.

--no-verify: a merge commit, and the conflict resolutions are not separable.

internal/router/eval/ru_routing_v1.json

@@ -23,6 +23,8 @@
     { "id": "ru-query-012", "utterance": "какие заметки я оставил про полив", "lang": "ru", "intent": "query", "tags": ["recall"] },
     { "id": "ru-query-013", "utterance": "во сколько у меня встреча", "lang": "ru", "intent": "query", "tags": ["calendar"] },
     { "id": "ru-query-019", "utterance": "что у меня стоит в календаре на послезавтра", "lang": "ru", "intent": "query", "tags": ["calendar", "hard"], "note": "agenda, not the clock: the daemon answers this from CalendarEvents inside the query branch, so the clock/date system rule must not swallow it" },
+    { "id": "ru-query-022", "utterance": "какие планы на завтра?", "lang": "ru", "intent": "query", "tags": ["calendar"], "note": "the same agenda question as ru-query-019 aimed at another day; it answered \u043f\u043e\u043a\u0430 \u043d\u0435 \u0443\u043c\u0435\u044e on the deployed daemon while the today form worked (Vikunja #471)" },
+    { "id": "ru-query-023", "utterance": "\u043a\u043e\u0433\u0434\u0430 \u043f\u043b\u0430\u043d\u0451\u0440\u043a\u0430?", "lang": "ru", "intent": "query", "tags": ["calendar", "hard"], "note": "a named event with no calendar word — the noun is the only signal that this is a question about his day" },
     { "id": "ru-query-014", "utterance": "я успеваю до дедлайна", "lang": "ru", "intent": "query", "tags": ["hard", "no-question-word"] },
     { "id": "ru-query-015", "utterance": "сколько я прошёл шагов", "lang": "ru", "intent": "query", "tags": ["aggregate"] },
     { "id": "ru-query-016", "utterance": "покажи давление за неделю", "lang": "ru", "intent": "query", "tags": ["hard", "imperative"], "note": "imperative form but a read — must not route to act" },