feat(hermes): first-class Hermes Agent support, plugin 0.2.0

The native Hermes plugin now resolves .planning/<slug>/ plans with the
same rules as the shell route (PLAN_ID, .planning/.active_plan, newest
slug, legacy root; slug validation, containment, BOM-tolerant pointer,
the inject-plan.sh nested-root ambiguity rule with a once-per-turn
notice, PWF_PLAN_ROOT fail-closed, PLANNING_DISABLED), answers Hermes'
pre_verify hook with the completion gate in gated mode using the
check-complete.sh decision table and state files, registers /pwf,
/pwf-status and /plan-status through ctx.register_command (the Markdown
command files were never loaded by Hermes), registers the bundled skill
from the plugin's own directory, creates gated and autonomous plans with
attestation from planning_with_files_init(name, mode), evaluates
completion in Python when sh is absent, and ships a shell-hook bridge
for Hermes config-file hooks.

The .hermes SKILL.md fixes the native Windows home (%LOCALAPPDATA%\hermes)
and documents the plugin surface; docs/hermes.md is rewritten from the
Hermes 0.19.1 source and a live install (CLI, Desktop, Windows, gate
limits, shell-hook route, import-agent migration); AGENTS.md, llms.txt
and docs/installation.md carry the Hermes route.

Verified live through Hermes' own plugin manager and scanned SAFE by
Hermes' skills-guard. An adversarial second-model review found four
divergences from the shell route in the first build; all are fixed and
covered by tests/test_hermes_first_class.py, including a differential
test against inject-plan.sh.