feat: Voice channel creation Flow (#11775)

This PR introduces a new channel type for voice conversations.

ref: #11481 

## Changes

- Add database migration for channel_voice table with phone_number and
provider_config
- Create Channel::Voice model with E.164 phone number validation and
Twilio config validation
- Add voice channel association to Account model
- Extend inbox helpers and types to support voice channels
- Add voice channel setup UI with Twilio configuration form
- Include voice channel in channel factory and list components
- Add API routes and store actions for voice channel creation
- Add comprehensive translations for voice channel management

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>

db/migrate/20250620120000_create_channel_voice.rb

@@ -0,0 +1,16 @@
+class CreateChannelVoice < ActiveRecord::Migration[7.0]
+  def change
+    create_table :channel_voice do |t|
+      t.string :phone_number, null: false
+      t.string :provider, null: false, default: 'twilio'
+      t.jsonb :provider_config, null: false
+      t.integer :account_id, null: false
+      t.jsonb :additional_attributes, default: {}
+
+      t.timestamps
+    end
+
+    add_index :channel_voice, :phone_number, unique: true
+    add_index :channel_voice, :account_id
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2025_05_23_031839) do
+ActiveRecord::Schema[7.1].define(version: 2025_06_20_120000) do
   # These extensions should be enabled to support this database
   enable_extension "pg_stat_statements"
   enable_extension "pg_trgm"
@@ -443,6 +443,18 @@ ActiveRecord::Schema[7.1].define(version: 2025_05_23_031839) do
     t.index ["account_id", "profile_id"], name: "index_channel_twitter_profiles_on_account_id_and_profile_id", unique: true
   end
 
+  create_table "channel_voice", force: :cascade do |t|
+    t.string "phone_number", null: false
+    t.string "provider", default: "twilio", null: false
+    t.jsonb "provider_config", null: false
+    t.integer "account_id", null: false
+    t.jsonb "additional_attributes", default: {}
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_channel_voice_on_account_id"
+    t.index ["phone_number"], name: "index_channel_voice_on_phone_number", unique: true
+  end
+
   create_table "channel_web_widgets", id: :serial, force: :cascade do |t|
     t.string "website_url"
     t.integer "account_id"
@@ -907,7 +919,7 @@ ActiveRecord::Schema[7.1].define(version: 2025_05_23_031839) do
     t.text "header_text"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.jsonb "config", default: {"allowed_locales"=>["en"]}
+    t.jsonb "config", default: {"allowed_locales" => ["en"]}
     t.boolean "archived", default: false
     t.bigint "channel_web_widget_id"
     t.index ["channel_web_widget_id"], name: "index_portals_on_channel_web_widget_id"