Quote parent's message in email replies

Add standard > -prefixed quote block to outbound replies so parents can
see what they wrote in the previous message, matching natural email client
behaviour. The quote header uses the German "Am <date> schrieb <addr>:"
convention (matching Outlook/Thunderbird).

- email_channel.py: add _build_quoted_block() helper; extend send_reply()
  with optional quoted_text/quoted_from params
- main.py: pass msg["body"] and msg["from"] as quoted_text/quoted_from

https://claude.ai/code/session_01HaUFs7SaLD5SoiuGCY27Tw

main.py

@@ -100,6 +100,8 @@ def run_poll_loop(agent: EmailAgent, channel: EmailChannel, poll_interval: int)
                             body=reply,
                             in_reply_to=msg["message_id"],
                             references=msg["references"],
+                            quoted_text=msg["body"],
+                            quoted_from=msg["from"],
                         )
                 except Exception:
                     logger.exception(

src/channels/email_channel.py

@@ -94,6 +94,23 @@ def _generate_message_id(from_addr: str) -> str:
     return f"<{time.time():.6f}.{id(from_addr)}@{domain}>"
 
 
+def _build_quoted_block(original_text: str, from_addr: str) -> str:
+    """Format original_text as a standard email quote block.
+
+    Produces the classic:
+
+        On <date>, <from> wrote:
+        > line 1
+        > line 2
+    """
+    date_str = time.strftime("%a, %d %b %Y %H:%M", time.localtime())
+    header = f"Am {date_str} schrieb {from_addr}:"
+    quoted_lines = "\n".join(
+        f"> {line}" for line in original_text.splitlines()
+    )
+    return f"\n\n{header}\n{quoted_lines}"
+
+
 # ---------------------------------------------------------------------------
 # Main class
 # ---------------------------------------------------------------------------
@@ -201,9 +218,14 @@ class EmailChannel:
         body: str,
         in_reply_to: str = "",
         references: str = "",
+        quoted_text: str = "",
+        quoted_from: str = "",
     ) -> str:
         """Send an email reply.
 
+        If quoted_text is provided it is appended to body as a standard
+        ``> ``-prefixed quote block so parents can see what they wrote.
+
         Returns the new Message-ID so the caller can track the thread.
         """
         new_message_id = _generate_message_id(self._from_email)
@@ -216,6 +238,10 @@ class EmailChannel:
         ref_parts = [r for r in [references, in_reply_to] if r]
         new_references = " ".join(ref_parts)
 
+        # Append quoted original message
+        if quoted_text.strip():
+            body = body + _build_quoted_block(quoted_text, quoted_from or to)
+
         msg = MIMEMultipart("alternative")
         msg["From"] = self._from_email
         msg["To"] = to