fix(cli): respect HERMES_HOME in all remaining hardcoded ~/.hermes paths

Several files resolved paths via Path.home() / ".hermes" or
os.path.expanduser("~/.hermes/..."), bypassing the HERMES_HOME
environment variable. This broke isolation when running multiple
Hermes instances with distinct HERMES_HOME directories.

Replace all hardcoded paths with calls to get_hermes_home() from
hermes_cli.config, consistent with the rest of the codebase.

Files fixed:
- tools/process_registry.py (processes.json)
- gateway/pairing.py (pairing/)
- gateway/sticker_cache.py (sticker_cache.json)
- gateway/channel_directory.py (channel_directory.json, sessions.json)
- gateway/config.py (gateway.json, config.yaml, sessions_dir)
- gateway/mirror.py (sessions/)
- gateway/hooks.py (hooks/)
- gateway/platforms/base.py (image_cache/, audio_cache/, document_cache/)
- gateway/platforms/whatsapp.py (whatsapp/session)
- gateway/delivery.py (cron/output)
- agent/auxiliary_client.py (auth.json)
- agent/prompt_builder.py (SOUL.md)
- cli.py (config.yaml, images/, pastes/, history)
- run_agent.py (logs/)
- tools/environments/base.py (sandboxes/)
- tools/environments/modal.py (modal_snapshots.json)
- tools/environments/singularity.py (singularity_snapshots.json)
- tools/tts_tool.py (audio_cache)
- hermes_cli/status.py (cron/jobs.json, sessions.json)
- hermes_cli/gateway.py (logs/, whatsapp session)
- hermes_cli/main.py (whatsapp/session)

Tests updated to use HERMES_HOME env var instead of patching Path.home().

Closes #892

(cherry picked from commit 78ac1bba43b8b74a934c6172f2c29bb4d03164b9)

gateway/delivery.py

@@ -15,6 +15,8 @@ from dataclasses import dataclass
 from typing import Dict, List, Optional, Any, Union
 from enum import Enum
 
+from hermes_cli.config import get_hermes_home
+
 logger = logging.getLogger(__name__)
 
 MAX_PLATFORM_OUTPUT = 4000
@@ -116,7 +118,7 @@ class DeliveryRouter:
         """
         self.config = config
         self.adapters = adapters or {}
-        self.output_dir = Path.home() / ".hermes" / "cron" / "output"
+        self.output_dir = get_hermes_home() / "cron" / "output"
     
     def resolve_targets(
         self,
@@ -256,7 +258,7 @@ class DeliveryRouter:
     def _save_full_output(self, content: str, job_id: str) -> Path:
         """Save full cron output to disk and return the file path."""
         timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-        out_dir = Path.home() / ".hermes" / "cron" / "output"
+        out_dir = get_hermes_home() / "cron" / "output"
         out_dir.mkdir(parents=True, exist_ok=True)
         path = out_dir / f"{job_id}_{timestamp}.txt"
         path.write_text(content)