session-memory: Claude + Codex + Grok distributors + registry (WP-0007 T02/T03)

Thin per-flavor distributors over the shared base: Claude (CLAUDE.md, optional
skill-stub mode), Codex (AGENTS.md), Grok (.grok/instructions.md). registry maps
flavor->distributor — adding a flavor is one entry + one module. Same agnostic
body renders to distinct per-flavor targets (FR-A3). 7 new tests; suite 117/117.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

session_memory/distribute/grok.py

@@ -0,0 +1,15 @@
+"""Grok distributor (PRD §6.4 FR-X1; T03).
+
+Renders an approved Solution Pattern into Grok's native instruction format. Defaults
+to a ``.grok/instructions.md`` snippet; the same agnostic body as the other flavors
+(FR-A3), overridable via ``rendering_hints["grok"]``.
+"""
+
+from __future__ import annotations
+
+from .base import BaseDistributor
+
+
+class GrokDistributor(BaseDistributor):
+    flavor = "grok"
+    target_path = ".grok/instructions.md"