refactor(restructure): git mv all source files into hermes_agent/ package

Pure file moves, zero content changes. Every file in agent/, tools/,
hermes_cli/, gateway/, acp_adapter/, cron/, and plugins/ moves into
hermes_agent/. Top-level modules (run_agent.py, cli.py, etc.) move to
their new homes per the restructure manifest.

Git sees 100% similarity on all moves.

Part of #14182, #14183

hermes_agent/tools/__init__.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+"""Tools package namespace.
+
+Keep package import side effects minimal. Importing ``tools`` should not
+eagerly import the full tool stack, because several subsystems load tools while
+``hermes_cli.config`` is still initializing.
+
+Callers should import concrete submodules directly, for example:
+
+    import tools.web_tools
+    from tools import browser_tool
+
+Python will resolve those submodules via the package path without needing them
+to be re-exported here.
+"""
+
+
+def check_file_requirements():
+    """File tools only require terminal backend availability."""
+    from .terminal_tool import check_terminal_requirements
+
+    return check_terminal_requirements()
+
+
+__all__ = ["check_file_requirements"]