feat(routing): add routing_rules schema, condition types, and action types (M4-001/002/003)

- Add routing_rules table to packages/db with scope, priority, conditions (jsonb), and action (jsonb) columns; generate migration 0004
- Define RoutingCondition, RoutingAction, RoutingRule, TaskClassification, and RoutingDecision types in apps/gateway/src/agent/routing/routing.types.ts
- Expand @mosaic/types routing/index.ts to export all M4 types (TaskType, Complexity, Domain, CostTier+local, Capability) alongside existing RoutingCriteria/RoutingResult
- Fix pre-existing type errors in routing.service.ts (local CostTier) and default-rules.ts (count optional chaining, unknown cast)
- Fix pre-existing Prettier violations in agent module and provider files

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/db/drizzle/meta/_journal.json

@@ -29,6 +29,13 @@
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       "tag": "0003_p8003_perf_indexes",
       "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "7",
+      "when": 1774224004898,
+      "tag": "0004_bumpy_miracleman",
+      "breakpoints": true
     }
   ]
 }