Release v0.6.0 - **Built-in Shell Autocompletion**: Added `ajourn completion [bash|zsh]` with dynamic plugin discovery (`ajourn-*`), tag suggestions (`-t`/`--tags`), and path autocompletion. - **Auto-loading Shell Integration**: Configured `GNUmakefile` to automatically install completion scripts to `$(PREFIX)/share/bash-completion/completions` and create auto-loading symlinks at `~/.bashrc.d/ajourn.bash` on Fedora/RHEL systems. - **Subcommand Usage Help System**: Implemented dedicated help pages for all subcommands (`init`, `log`, `state`, `search`, `startup`, `heritage`, `migrate`, `tidy`, `verify`, `rechain`, `completion`). All subcommands now respond to `--help`, `-h`, `help`, and `ajourn help <subcommand>`. - **Official `pjp` AI Agent Skill**: Created `skills/pjp/SKILL.md` (PJP v0.6.0) providing complete guidelines for AI agents adopting PJP. Deprecated and removed legacy `project-journal` skill. - **Upgrade Guide**: Added `UPGRADE.rst` documenting step-by-step procedures for upgrading binaries, autocompletion scripts, AI agent skills, and legacy journal stores. - **Test Suite Expansion**: Added `Test 10: Shell Completion` and `Test 11: Subcommand Help Pages` to `tests/run_tests.sh`. - Added **Consult Journal Memory First** directive to `AGENTS.md` and `README.rst` mandating that AI agents inspect `ajourn startup` output and past journal entries before executing exploratory system discovery commands. - Added **Zero-Ambiguity AI Agent Implementation Guide** to `AGENTS.md` and `README.rst` providing a deterministic 5-step quickstart for any AI agent receiving instructions to adopt PJP. - Documented **Plugin & Extension Architecture** in `AGENTS.md` and `README.rst` detailing Git-style executable delegation (`ajourn-<subcommand>`) and lifecycle event hooks (`.agents/journal/hooks/`).