Cowork hook integration for SessionEnd capture

[Paul-Kyle]

What

Mirror the Claude Code SessionEnd hook integration (shipped in #32) for Cowork. When a Cowork session ends — including /clear, logout, or normal exit — auto-capture a snapshot to palinode-api.

Context

#32 landed palinode init which scaffolds .claude/CLAUDE.md, .claude/settings.json, .claude/hooks/palinode-session-end.sh, and .mcp.json in a project. Claude Code has a documented hook surface with a SessionEnd event and matcher: \"clear\" value that fires on /clear, so the integration is straightforward.

Cowork's hook model is different and, as of 2026-04, not fully documented:

• The official help center documents global instructions, folder instructions, plugins, scheduled tasks, and connectors — but no first-class SessionEnd-style hook API.
• A GitHub issue ([BUG] Cowork: Plugin hooks from hooks/hooks.json never fire — --setting-sources user excludes plugin scope anthropics/claude-code#27398) suggests plugin hooks via `hooks/hooks.json` may exist but are unreliable in Cowork Desktop sessions.
• Practical integration path today is probably via plugin skills / global instructions that remind the agent to call `palinode_session_end` rather than a lifecycle hook.

Scope

• Verify current Cowork hook surface (read docs, test `hooks/hooks.json` in a Cowork plugin)
• If lifecycle hooks work: add a Cowork branch to `palinode init` that writes the equivalent config
• If not: ship a Cowork-flavored skill or global-instructions template that prompts `palinode_session_end` before `/clear`
• Add a `--surface cowork` flag to `palinode init` (or auto-detect)
• Document in `examples/hooks/` and `docs/INSTALL-CLAUDE-CODE.md` (rename to `INSTALL.md`?)

Depends on

• CLAUDE.md integration — zero-friction adoption path #32 (shipped) — reuse the Claude Code hook script as-is if Cowork's hook schema is compatible