Bump version to 0.2.0 to match release tag

Replace logo with new MyChatArchive book logo and update README

Add community standards: code of conduct, contributing, security, templates

Polish: fix cli typo, sync ROADMAP with features, add chunker to README structure

README: add MyChatArchive heading below logo

README: refine Why section, reduce logo size

Fix README: correct Why section, add logo to repo

Change license from MIT to AGPL-3.0

Proportional thread summaries + config + summarizer fixes

Add config support for summarize (model, base_url, api_key)

feat: time filters, sort by time, get_current_datetime, date injection

feat: add platform filter to search and MCP tools

feat: variable context-aware chunking for embeddings

fix: clarify default choices in init prompts (Choose [1] -> default 1)

docs: badges, fix em dashes, restore CLI flag formatting