feat(captain): allow agents to report Captain messages (#14799)

Adds a cloud-only flow for agents to flag incorrect or problematic
Captain (AI) responses. Right-clicking a Captain message surfaces a
"Report message" option that opens a dialog to pick a problem type and
add a description, persisted to a new captain_message_reports table for
the team to review.


<img width="636" height="542" alt="Screenshot 2026-06-20 at 9 15 56 AM"
src="https://github.com/user-attachments/assets/afaa233d-6bd6-455a-8a33-a3796a3e3ef6"
/>
<img width="580" height="502" alt="Screenshot 2026-06-20 at 9 16 03 AM"
src="https://github.com/user-attachments/assets/2d220d99-98cc-4c5e-a325-778ceb4f7bc9"
/>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

db/migrate/20260620000000_create_captain_message_reports.rb

@@ -0,0 +1,14 @@
+class CreateCaptainMessageReports < ActiveRecord::Migration[7.1]
+  def change
+    create_table :captain_message_reports do |t|
+      t.references :account, null: false
+      t.references :conversation, null: false
+      t.references :message, null: false
+      t.references :user, null: false
+      t.string :report_reason, null: false
+      t.text :description
+
+      t.timestamps
+    end
+  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: 2026_06_11_184600) do
+ActiveRecord::Schema[7.1].define(version: 2026_06_20_000000) do
   # These extensions should be enabled to support this database
   enable_extension "pg_stat_statements"
   enable_extension "pg_trgm"
@@ -399,6 +399,21 @@ ActiveRecord::Schema[7.1].define(version: 2026_06_11_184600) do
     t.index ["inbox_id"], name: "index_captain_inboxes_on_inbox_id"
   end
 
+  create_table "captain_message_reports", force: :cascade do |t|
+    t.bigint "account_id", null: false
+    t.bigint "conversation_id", null: false
+    t.bigint "message_id", null: false
+    t.bigint "user_id", null: false
+    t.string "report_reason", null: false
+    t.text "description"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_captain_message_reports_on_account_id"
+    t.index ["conversation_id"], name: "index_captain_message_reports_on_conversation_id"
+    t.index ["message_id"], name: "index_captain_message_reports_on_message_id"
+    t.index ["user_id"], name: "index_captain_message_reports_on_user_id"
+  end
+
   create_table "captain_scenarios", force: :cascade do |t|
     t.string "title"
     t.text "description"