fix: retain stock identities in research and AI task lists

internal/model/backtest.go

@@ -27,6 +27,7 @@ type ResearchInput struct {
 	Parameters StrategyParameters `json:"parameters"`
 }
 type BacktestRun struct {
+	Symbol            string          `json:"symbol"`
 	ID                string          `db:"id" json:"id"`
 	StrategyVersionID string          `db:"strategy_version_id" json:"strategy_version_id"`
 	Status            string          `db:"status" json:"status"`

internal/model/candidate_analysis.go

@@ -23,6 +23,9 @@ type AIConclusion struct {
 	MissingInformation []string `json:"missing_information"`
 }
 type CandidateAnalysis struct {
+	Name                string        `json:"name,omitempty"`
+	Symbol              string        `json:"symbol,omitempty"`
+	Exchange            string        `json:"exchange,omitempty"`
 	ID                  string        `db:"id" json:"id"`
 	CandidateRevisionID string        `db:"candidate_revision_id" json:"candidate_revision_id"`
 	InputVersion        int64         `db:"input_version" json:"input_version"`