Initial commit on Forgejo

Fresh repository history for elektrine/tarakan hosted at
https://git.elektrine.com/elektrine/tarakan.

priv/repo/migrations/20260725120100_create_finding_regressions.exs

@@ -0,0 +1,29 @@
+defmodule Tarakan.Repo.Migrations.CreateFindingRegressions do
+  use Ecto.Migration
+
+  def change do
+    create table(:finding_regressions) do
+      add :canonical_finding_id, references(:canonical_findings, on_delete: :delete_all),
+        null: false
+
+      add :repository_id, references(:repositories, on_delete: :delete_all), null: false
+      # The commit the finding was last believed fixed at, and when.
+      add :fixed_commit_sha, :string
+      add :fixed_at, :utc_datetime_usec
+      # The commit the finding was seen at again.
+      add :detected_commit_sha, :string, null: false
+      add :detected_by_scan_id, references(:scans, on_delete: :nilify_all)
+
+      timestamps(type: :utc_datetime_usec)
+    end
+
+    # One regression row per (finding, reappearance commit) keeps repeated
+    # scans of the same commit from stacking duplicates. Named explicitly
+    # because the derived name exceeds Postgres's 63-character identifier cap.
+    create unique_index(:finding_regressions, [:canonical_finding_id, :detected_commit_sha],
+             name: :finding_regressions_unique_detection_index
+           )
+
+    create index(:finding_regressions, [:repository_id, :inserted_at])
+  end
+end