release: sync public v0.8.6

[Paul-Kyle]

Summary

• sync the public repo to v0.8.6 from palinode-dev origin/main
• fix wheel packaging to include palinode.diagnostics, palinode.diagnostics.checks, palinode.import_, and palinode.lint
• add Roo Cline + JetBrains MCP docs and the transport decision guide
• fix the palinode init SessionEnd hook scaffold to use jq slurp extraction

Validation

• uv run --extra dev pytest tests/test_cli_init.py tests/test_mcp_config_diagnose.py
• bash scripts/check-shipping-leaks.sh
• editable install check on reconciled dev origin/main (56bc73a)