build(deps): consolidate dependabot updates (#447)

Update multiple dependencies across components:

patcher:
- langgraph-checkpoint 2.1.1 → 3.0.1 (major version, drops Python 3.9 support)
- langgraph 0.6.6 → 0.6.11
- marshmallow 3.26.1 → 3.26.2 (CVE-2025-68480 fix)
- mcp 1.13.0 → 1.26.0
- starlette 0.47.2 → 0.52.1 (security fix for Range header parsing)

program-model:
- mcp 1.13.0 → 1.26.0
- starlette 0.47.2 → 0.52.1 (security fix for Range header parsing)

seed-gen:
- langgraph-checkpoint 2.1.0 → 3.0.1
- langgraph 0.6.6 → 0.6.11

This consolidates the following Dependabot PRs: #430, #433, #434, #443, #444, #445, #446

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: hbrodin

patcher/pyproject.toml

@@ -10,7 +10,7 @@ dependencies = [
     "common[full]",
     "langchain-community ~=0.3.27",
     "langgraph ~=0.6.6",
-    "langgraph-checkpoint ~=2.1.1",
+    "langgraph-checkpoint >=3.0.0",
     "openai ~=1.100.2",
     "program-model",
     "pydantic-settings ~=2.7.1",