Implement platform skill execution system and fix message formatting

Major features:
- Added platform skill execution architecture allowing agent to invoke
  platform-specific actions (delete posts, update rules, announcements)
- Agent now receives available platform skills and can execute them with
  proper authorization checks via constitution

Agent improvements:
- Added platform_skills parameter to process_request()
- New action type: execute_platform_skill with skill_name and skill_parameters
- Enhanced LLM prompts to distinguish between direct execution and skill execution
- Clearer JSON format specifications for different action types

Bot orchestration:
- Bot fetches platform skills and passes to agent
- Detects execute_platform_skill actions and calls platform.execute_skill()
- Handles skill execution results with proper error reporting

Mastodon platform:
- Implemented create_announcement skill with graceful API limitation handling
- Implemented update_instance_rules skill with graceful API limitation handling
- Both skills now acknowledge Mastodon API doesn't support these operations
  programmatically and provide direct admin interface links
- Implemented delete_status skill (working)
- All admin operations use direct API calls via __api_request

Message formatting fixes:
- Fixed message chunking to preserve line breaks and paragraph structure
- Split by paragraphs first, then lines, then words as last resort
- Removed debug logging for newline tracking

Documentation:
- Updated .gitignore to exclude bot.log and nohup.out

This implements the governance bot's ability to execute platform-specific
actions while respecting constitutional authority and handling API limitations
gracefully.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/govbot/platforms/mastodon.py

@@ -587,20 +587,27 @@ class MastodonAdapter(PlatformAdapter):
         }
 
     def _update_instance_rules(self, params: Dict[str, Any]) -> Dict[str, Any]:
-        """Update instance rules"""
-        # Note: This requires admin API access
-        # Implementation depends on Mastodon version and API availability
-        rules = params["rules"]
+        """Update instance rules - web admin only"""
+        rules = params.get("rules", [])
 
-        # This would use admin API to update instance rules
-        # Exact implementation varies by Mastodon version
+        # Note: Mastodon's API does not provide endpoints for creating/updating rules.
+        # Rules must be managed through the web admin interface.
+        # See: https://docs.joinmastodon.org/methods/instance/
+
+        rules_text = "\n".join([f"- {rule}" for rule in rules])
 
         return {
-            "success": True,
-            "message": f"Updated instance rules ({len(rules)} rules)",
+            "success": False,
+            "message": (
+                f"Proposed server rules:\n{rules_text}\n\n"
+                "Note: Mastodon's API does not support managing server rules programmatically. "
+                f"To update the server rules, please visit:\n"
+                f"{self.instance_url}/admin/server_settings/rules\n\n"
+                "You can add, edit, or remove rules through the admin interface."
+            ),
             "data": {"rules": rules},
-            "reversible": True,
-            "reverse_params": {"rules": "previous_rules"},  # Would need to store previous
+            "reversible": False,
+            "requires_manual_action": True,
         }
 
     def _update_instance_description(self, params: Dict[str, Any]) -> Dict[str, Any]:
@@ -649,23 +656,35 @@ class MastodonAdapter(PlatformAdapter):
         }
 
     def _create_announcement(self, params: Dict[str, Any]) -> Dict[str, Any]:
-        """Create instance announcement"""
+        """Create instance announcement - web admin only"""
         text = params["text"]
         starts_at = params.get("starts_at")
         ends_at = params.get("ends_at")
 
-        announcement = self.client.admin_announcement_create(
-            text=text,
-            starts_at=starts_at,
-            ends_at=ends_at,
-        )
+        # Note: Mastodon's API does not provide endpoints for creating announcements.
+        # Announcements must be created through the web admin interface.
+        # See: https://docs.joinmastodon.org/methods/announcements/
+
+        timing_info = ""
+        if starts_at or ends_at:
+            timing_info = "\n\nTiming:"
+            if starts_at:
+                timing_info += f"\n- Start: {starts_at}"
+            if ends_at:
+                timing_info += f"\n- End: {ends_at}"
 
         return {
-            "success": True,
-            "message": "Created announcement",
-            "data": {"announcement_id": announcement["id"], "text": text},
-            "reversible": True,
-            "reverse_params": {"announcement_id": announcement["id"]},
+            "success": False,
+            "message": (
+                f"Announcement text:\n{text}{timing_info}\n\n"
+                "Note: Mastodon's API does not support creating announcements programmatically. "
+                f"To post this announcement, please visit:\n"
+                f"{self.instance_url}/admin/announcements\n\n"
+                "Click 'New announcement', paste the text above, and publish it."
+            ),
+            "data": {"text": text, "starts_at": starts_at, "ends_at": ends_at},
+            "reversible": False,
+            "requires_manual_action": True,
         }
 
     def _strip_markdown(self, text: str) -> str: