From 7c69086fa586b3007d23505db557cc13c15af628 Mon Sep 17 00:00:00 2001
From: David Gwilliam <dhgwilliam@gmail.com>
Date: Mon, 16 Mar 2026 20:53:02 -0700
Subject: [PATCH] refactor(deprecate): Add deprecation warning to RenderStage
 (Phase 4.1)

- Add DeprecationWarning to RenderStage.__init__()
- Document that RenderStage uses legacy rendering code
- Recommend modern pipeline stages as replacement
- ItemsStage already has deprecation warning
- Tests pass (515 core tests, legacy failures pre-existing)
---
 engine/pipeline/adapters.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/engine/pipeline/adapters.py b/engine/pipeline/adapters.py
index 442ef50..0f5ff38 100644
--- a/engine/pipeline/adapters.py
+++ b/engine/pipeline/adapters.py
@@ -18,6 +18,11 @@ class RenderStage(Stage):
     - Selects headlines and renders them to blocks
     - Applies camera scroll position
     - Adds firehose layer if enabled
+
+    .. deprecated::
+        RenderStage uses legacy rendering from engine.legacy.layers and engine.legacy.render.
+        This stage will be removed in a future version. For new code, use modern pipeline stages
+        like PassthroughStage with custom rendering stages instead.
     """
 
     def __init__(
@@ -30,6 +35,15 @@ class RenderStage(Stage):
         firehose_enabled: bool = False,
         name: str = "render",
     ):
+        import warnings
+
+        warnings.warn(
+            "RenderStage is deprecated. It uses legacy rendering code from engine.legacy.*. "
+            "This stage will be removed in a future version. "
+            "Use modern pipeline stages with PassthroughStage or create custom rendering stages instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
         self.name = name
         self.category = "render"
         self.optional = False