heartbeat: notify Michael by email when each queued task completes

Adds notify_task_complete/3 called after every queue task resolves
(done, blocked, or failed). Posts to Telepathy's POST /email endpoint.
Also adds :inets and :ssl to extra_applications so :httpc is available.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/symbiont/heartbeat.ex

@@ -120,12 +120,15 @@ defmodule Symbiont.Heartbeat do
                 "Heartbeat: task #{task["id"]} returned but self-reported blocked — marking blocked"
               )
               Symbiont.Queue.block(task["id"], text)
+              notify_task_complete(task, :blocked, text)
             else
               Symbiont.Queue.complete(task["id"], text)
+              notify_task_complete(task, :done, text)
             end
 
           {:error, reason} ->
             Symbiont.Queue.fail(task["id"], inspect(reason))
+            notify_task_complete(task, :failed, inspect(reason))
         end
       end)
     end)
@@ -186,4 +189,56 @@ defmodule Symbiont.Heartbeat do
   defp schedule_next(interval) do
     Process.send_after(self(), :tick, interval)
   end
+
+  defp notify_task_complete(task, status, result) do
+    task_id = task["id"] || "unknown"
+    task_desc = task["task"] || ""
+    priority = task["priority"] || "normal"
+
+    subject =
+      case status do
+        :done -> "Task done [#{priority}]: #{String.slice(task_desc, 0, 60)}"
+        :blocked -> "Task blocked [#{priority}]: #{String.slice(task_desc, 0, 60)}"
+        :failed -> "Task failed [#{priority}]: #{String.slice(task_desc, 0, 60)}"
+      end
+
+    snippet = String.slice(result || "", 0, 800)
+
+    body = """
+    Task #{task_id} completed with status: #{status}
+
+    Description:
+    #{task_desc}
+
+    Result:
+    #{snippet}
+
+    Muse
+    """
+
+    payload =
+      Jason.encode!(%{
+        to: "mdwyer@michaelmdwyer.com",
+        subject: subject,
+        body: body,
+        from_name: "Muse"
+      })
+
+    url = ~c"http://localhost:8114/email"
+
+    try do
+      :httpc.request(
+        :post,
+        {url, [], ~c"application/json", payload},
+        [{:timeout, 10_000}],
+        []
+      )
+
+      Logger.info("Task notification sent: #{task_id} → #{status}")
+    rescue
+      e -> Logger.warning("Task notification failed for #{task_id}: #{Exception.message(e)}")
+    catch
+      _, reason -> Logger.warning("Task notification failed for #{task_id}: #{inspect(reason)}")
+    end
+  end
 end

mix.exs

@@ -15,7 +15,7 @@ defmodule Symbiont.MixProject do
 
   def application do
     [
-      extra_applications: [:logger, :crypto],
+      extra_applications: [:logger, :crypto, :inets, :ssl],
       mod: {Symbiont.Application, []}
     ]
   end