ref(metrics): Store Conversation Run metrics as rows

packages/junior/migrations/0042_conversation_metrics.sql

@@ -0,0 +1,26 @@
+CREATE TABLE "junior_conversation_metrics" (
+	"conversation_id" text NOT NULL,
+	"run_id" text NOT NULL,
+	"metric" text NOT NULL,
+	"value" double precision NOT NULL,
+	"occurred_at" timestamp with time zone NOT NULL,
+	"updated_at" timestamp with time zone NOT NULL,
+	CONSTRAINT "junior_conversation_metrics_conversation_id_run_id_metric_pk" PRIMARY KEY("conversation_id","run_id","metric")
+);
+--> statement-breakpoint
+ALTER TABLE "junior_conversation_metrics" ADD CONSTRAINT "junior_conversation_metrics_conversation_id_junior_conversations_conversation_id_fk" FOREIGN KEY ("conversation_id") REFERENCES "public"."junior_conversations"("conversation_id") ON DELETE no action ON UPDATE no action;--> statement-breakpoint
+CREATE INDEX "junior_conversation_metrics_occurred_at_metric_idx" ON "junior_conversation_metrics" USING btree ("occurred_at","metric");--> statement-breakpoint
+INSERT INTO "junior_conversation_metrics" ("conversation_id", "run_id", "metric", "value", "occurred_at", "updated_at")
+SELECT conversation_id, coalesce(metric_run_id, 'legacy:' || conversation_id), metric, value, updated_at, updated_at
+FROM junior_conversations
+CROSS JOIN LATERAL (VALUES
+  ('duration_ms', duration_ms::double precision),
+  ('total_tokens', CASE WHEN coalesce(usage_json->>'inputTokens', usage_json->>'outputTokens', usage_json->>'cachedInputTokens', usage_json->>'cacheCreationTokens') IS NOT NULL THEN coalesce((usage_json->>'inputTokens')::double precision, 0) + coalesce((usage_json->>'outputTokens')::double precision, 0) + coalesce((usage_json->>'cachedInputTokens')::double precision, 0) + coalesce((usage_json->>'cacheCreationTokens')::double precision, 0) ELSE (usage_json->>'totalTokens')::double precision END),
+  ('input_tokens', (usage_json->>'inputTokens')::double precision),
+  ('output_tokens', (usage_json->>'outputTokens')::double precision),
+  ('cached_input_tokens', (usage_json->>'cachedInputTokens')::double precision),
+  ('cache_creation_tokens', (usage_json->>'cacheCreationTokens')::double precision),
+  ('reasoning_tokens', (usage_json->>'reasoningTokens')::double precision),
+  ('cost_usd', CASE WHEN usage_json->'cost'->>'total' IS NOT NULL THEN (usage_json->'cost'->>'total')::double precision WHEN coalesce(usage_json->'cost'->>'input', usage_json->'cost'->>'output', usage_json->'cost'->>'cacheRead', usage_json->'cost'->>'cacheWrite') IS NOT NULL THEN coalesce((usage_json->'cost'->>'input')::double precision, 0) + coalesce((usage_json->'cost'->>'output')::double precision, 0) + coalesce((usage_json->'cost'->>'cacheRead')::double precision, 0) + coalesce((usage_json->'cost'->>'cacheWrite')::double precision, 0) END)
+) AS metric_rows(metric, value)
+WHERE value IS NOT NULL AND value >= 0;