Merge PR #1278 to guide llm grep using timestamp

Fix(prompt): guide llm grep using timestamp

nanobot/agent/context.py

@@ -68,7 +68,7 @@ You are nanobot, a helpful AI assistant.
 ## Workspace
 Your workspace is at: {workspace_path}
 - Long-term memory: {workspace_path}/memory/MEMORY.md (write important facts here)
-- History log: {workspace_path}/memory/HISTORY.md (grep-searchable)
+- History log: {workspace_path}/memory/HISTORY.md (grep-searchable). Each entry starts with [YYYY-MM-DD HH:MM].
 - Custom skills: {workspace_path}/skills/{{skill-name}}/SKILL.md
 
 ## nanobot Guidelines

nanobot/skills/memory/SKILL.md

@@ -9,7 +9,7 @@ always: true
 ## Structure
 
 - `memory/MEMORY.md` — Long-term facts (preferences, project context, relationships). Always loaded into your context.
-- `memory/HISTORY.md` — Append-only event log. NOT loaded into context. Search it with grep.
+- `memory/HISTORY.md` — Append-only event log. NOT loaded into context. Search it with grep. Each entry starts with [YYYY-MM-DD HH:MM].
 
 ## Search Past Events