Add easy-memory skill

[memeda230606]

Summary

• store experimental easy-memory logs under ./easy-memory relative to the current working directory
• remove global-install restriction from experimental scripts and clarify log location in SKILL.md
• handle missing log directories in experimental search/list flows
• create today's log when missing and emit friendly empty-log/no-match messages in read/search workflows
• require explicit one-time initialization via scripts/init_memory.py and gate other scripts on init.log
• document initialization behavior and add init script entry in SKILL.md
• ignore local easy-memory/ logs in git
• append a formal reminder to search results when matches are found
• relax ASCII-only enforcement for content/keywords to allow UTF-8
• make read/search rules session-start only unless needed
• remove absolute script path from AGENTS.MD rules and document the path guidance in SKILL.md

Tests

• Not run (docs/input validation changes only)
• python3 skills/.experimental/easy-memory/scripts/read_today_log.py (run in temp working directory)
• python3 skills/.experimental/easy-memory/scripts/search_memory.py foo --max-results 5
• python3 skills/.experimental/easy-memory/scripts/write_memory.py --content "hello world" --factual true --ref-level low
• python3 skills/.experimental/easy-memory/scripts/search_memory.py zzz --max-results 5
• rm -f easy-memory/init.log
• python3 skills/.experimental/easy-memory/scripts/init_memory.py
• python3 skills/.experimental/easy-memory/scripts/read_today_log.py (post-init)
• python3 skills/.experimental/easy-memory/scripts/search_memory.py search --max-results 1

[memeda230606]

@gverma-openai Could you please take a look and review this PR? Thanks!