- Move copilotChatSessions, remoteAgentHost, and agentHost providers from
contrib/ into a new contrib/providers/ subfolder for clearer separation
- Add ESLint layer rule 'contrib/providers/*/~' (before 'contrib/*/~') so
sibling contrib folders cannot import directly from providers
- Update all entry points (sessions.common.main.ts, sessions.desktop.main.ts,
sessions.web.main.ts) to reference new provider paths
- Port all upstream changes from origin/main to the new provider locations
- Add contrib/providers entry to build/lib/i18n.resources.json
- Rewrite docs: README.md, LAYOUT.md, LAYERS.md, SESSIONS.md, SKILL.md,
sessions.instructions.md; add source-code-organization, coding-guidelines,
and writing-tests instruction files; remove stale SESSIONS_PROVIDER.md and
AGENTS_CHAT_WIDGET.md
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>