fix(hermes): honor HERMES_HOME for adapter paths

[jimmyzheng1027]

Pull Request Summary

Make the Hermes host adapter resolve its home from HERMES_HOME, with the existing ~/.hermes location retained as the fallback.

---

What does this PR do?

• Centralizes Hermes home, SOUL.md, and state.db path resolution.
• Uses HERMES_HOME for native Windows installs, profiles, and containers.
• Preserves explicit --path and --session-dir overrides.
• Adds coverage for Windows-style paths containing spaces, percent signs, hash characters, and non-ASCII text.
• Updates the packaged Hermes install, bridging, and uninstall instructions. The repository README is unchanged.

---

Why is this change needed?

The Hermes Windows installer uses %LOCALAPPDATA%\\hermes, while the adapter previously assumed ~/.hermes. That mismatch could inject memU guidance into the wrong SOUL.md and read sessions from the wrong state.db.

macOS behavior remains compatible because an unset or blank HERMES_HOME still resolves to Path.home() / ".hermes", which is the previous location.

---

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / cleanup
• Other (please explain)

---

PR Quality Checklist

• PR title follows an allowed format (for example feat:, fix:, docs:, memory base:)
• Changes are limited in scope and easy to review
• Documentation updated where applicable
• No breaking changes (or clearly documented)
• Related issues or discussions linked (not applicable; no issue was provided)

---

Testing

• python -m pytest tests/test_host_instruction.py tests/test_host_sessions.py tests/test_scheduling_windows.py -q -p no:cacheprovider — 77 passed
• ruff check and ruff format --check on touched Python files — passed
• mypy on touched Python files — passed

---

Optional

• Screenshots or examples added (not applicable)
• Edge cases considered
• Follow-up tasks mentioned (not applicable)