feat: add discovery tech stack and language contributions schema

- Introduced a new field `discovery_tech_stack` to the User schema, allowing for an array of strings.
- Created a migration to add the `discovery_tech_stack` field to the users table and populate it based on the existing `tech_stack`.
- Added a new migration for the `language_contributions` table, including fields for user ID, language, pull requests count, and contribution percentage.

Author: zcesur

lib/algora/accounts/schemas/user.ex

@@ -39,6 +39,7 @@ defmodule Algora.Accounts.User do
     field :stargazers_count, :integer, default: 0
     field :domain, :string
     field :tech_stack, {:array, :string}, default: []
+    field :discovery_tech_stack, {:array, :string}, default: []
     field :categories, {:array, :string}, default: []
     field :featured, :boolean, default: false
     field :priority, :integer, default: 0

priv/repo/migrations/20250708115448_create_language_contributions.exs

@@ -0,0 +1,18 @@
+defmodule Algora.Repo.Migrations.CreateLanguageContributions do
+  use Ecto.Migration
+
+  def change do
+    create table(:language_contributions) do
+      add :user_id, :string, null: false
+      add :language, :citext, null: false
+      add :prs, :integer, null: false
+      add :percentage, :decimal, null: false
+
+      timestamps()
+    end
+
+    create unique_index(:language_contributions, [:user_id, :language])
+    create index(:language_contributions, [:user_id])
+    create index(:language_contributions, [:language])
+  end
+end

priv/repo/migrations/20250708122536_add_discovery_tech_stack_to_users.exs

@@ -0,0 +1,17 @@
+defmodule Algora.Repo.Migrations.AddDiscoveryTechStackToUsers do
+  use Ecto.Migration
+
+  def up do
+    alter table(:users) do
+      add :discovery_tech_stack, {:array, :citext}, default: []
+    end
+
+    execute("UPDATE users SET discovery_tech_stack = tech_stack WHERE tech_stack != '{}'")
+  end
+
+  def down do
+    alter table(:users) do
+      remove :discovery_tech_stack
+    end
+  end
+end