docs(alerts): rules + CLAUDE.md — inbox redesign, V17 migration

- .claude/rules/ui.md: rewrite Alerts section — sidebar trims to
  Inbox/Rules/Silences, InboxPage description updated (4 filters, row
  actions, bulk toolbar, soft-delete undo), SilenceRuleMenu documented,
  SilencesPage ?ruleId= prefill noted.
- CLAUDE.md: V17 migration entry describing enum/column/table/index
  changes for the inbox redesign.
- .claude/rules/app-classes.md AlertController bullet already updated
  in the T6 drive-by.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -73,6 +73,7 @@ PostgreSQL (Flyway): `cameleer-server-app/src/main/resources/db/migration/`
 - V14 — Repair EXCHANGE_MATCH alert_rules persisted with fireMode=null (sets fireMode=PER_EXCHANGE + perExchangeLingerSeconds=300); paired with stricter `ExchangeMatchCondition` ctor that now rejects null fireMode.
 - V15 — Discriminate open-instance uniqueness by `context->'exchange'->>'id'` so EXCHANGE_MATCH/PER_EXCHANGE emits one alert_instance per matching exchange; scalar kinds resolve to `''` and keep one-open-per-rule.
 - V16 — Generalise the V15 discriminator to prefer `context->>'_subjectFingerprint'` (falls back to the V15 `exchange.id` expression for legacy rows). Enables AGENT_LIFECYCLE to emit one alert_instance per `(agent, eventType, timestamp)` via a canonical fingerprint in the evaluator firing's context.
+- V17 — Alerts inbox redesign: drop `ACKNOWLEDGED` from `alert_state_enum` (ack is now orthogonal via `acked_at`), add `read_at` + `deleted_at` timestamp columns (global, no per-user tracking), drop `alert_reads` table entirely, rework the V13/V15/V16 open-rule unique index predicate to `state IN ('PENDING','FIRING') AND deleted_at IS NULL` so ack doesn't close the slot and soft-delete frees it.
 
 ClickHouse: `cameleer-server-app/src/main/resources/clickhouse/init.sql` (run idempotently on startup)