feat(channels): listen on #development (KDF-derived PSK)

Add #development to the built-in hashtag channel set; its PSK is
derived from the channel name via the standard MeshCore hashtag KDF.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

orac/ai.py

@@ -50,10 +50,20 @@ def _shorten_with_claude(text: str, max_chars: int) -> str:
             model="claude-sonnet-4-6",
             max_tokens=256,
             timeout=CLAUDE_TIMEOUT_S,
+            system=(
+                "You rewrite a message to fit within a strict character budget. "
+                "Output ONLY the rewritten message — no preamble, no quotes, no "
+                "explanation, no commentary, no labels, no character count. "
+                "Preserve the original meaning, tone, and voice. Plain text only."
+            ),
             messages=[
                 {
                     "role": "user",
-                    "content": f"Shorten this to {max_chars} characters: {text}",
+                    "content": (
+                        f"Rewrite the following message so it is at most "
+                        f"{max_chars} characters. Reply with the rewritten "
+                        f"message only.\n\n{text}"
+                    ),
                 }
             ],
         )

orac/crypto.py

@@ -256,6 +256,7 @@ _BUILTIN_HASHTAG_CHANNELS: tuple[str, ...] = (
     "#weather",
     "#protest",
     # --- Dev / testing ---
+    "#development",
     "#devtest",
     "#devtestdevtest",
 )