stage-11: security hardening

- Prompt injection protection: external messages wrapped in [EXTERNAL CONTENT]
  markers, system prompt instructs Claude to never follow external instructions
- Invocation logging: all Claude CLI calls logged with channel, model, duration,
  token counts to echo-core.invoke logger
- Security logging: separate echo-core.security logger for unauthorized access
  attempts (DMs from non-admins, unauthorized admin/owner commands)
- Security log routed to logs/security.log in addition to main log
- Extended echo doctor: Claude CLI functional check, config.json secret scan,
  .gitignore completeness, file permissions, Ollama reachability, bot process
- Subprocess env stripping logged at debug level

373 tests pass (10 new security tests).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_cli.py

@@ -100,15 +100,40 @@ class TestDoctor:
 
     def _run_doctor(self, iso, capsys, *, token="tok",
                     claude="/usr/bin/claude",
-                    disk_bavail=1_000_000, disk_frsize=4096):
+                    disk_bavail=1_000_000, disk_frsize=4096,
+                    setup_full=False):
         """Run cmd_doctor with mocked externals, return (stdout, exit_code)."""
+        import os as _os
         stat = MagicMock(f_bavail=disk_bavail, f_frsize=disk_frsize)
+
+        # Mock subprocess.run for claude --version
+        mock_proc = MagicMock(returncode=0, stdout="1.0.0", stderr="")
+
+        # Mock urllib for Ollama reachability
+        mock_resp = MagicMock(status=200)
+
         patches = [
             patch("cli.get_secret", return_value=token),
             patch("keyring.get_password", return_value=None),
             patch("shutil.which", return_value=claude),
             patch("os.statvfs", return_value=stat),
+            patch("subprocess.run", return_value=mock_proc),
+            patch("urllib.request.urlopen", return_value=mock_resp),
         ]
+
+        if setup_full:
+            # Create .gitignore with required entries
+            gi_path = cli.PROJECT_ROOT / ".gitignore"
+            gi_path.write_text("sessions/\nlogs/\n.env\n*.sqlite\n")
+            # Create PID file with current PID
+            iso["pid_file"].write_text(str(_os.getpid()))
+            # Set config.json not world-readable
+            iso["config_file"].chmod(0o600)
+            # Create sessions dir not world-readable
+            sessions_dir = cli.PROJECT_ROOT / "sessions"
+            sessions_dir.mkdir(exist_ok=True)
+            sessions_dir.chmod(0o700)
+
         with ExitStack() as stack:
             for p in patches:
                 stack.enter_context(p)
@@ -120,7 +145,7 @@ class TestDoctor:
 
     def test_all_pass(self, iso, capsys):
         iso["config_file"].write_text('{"bot":{}}')
-        out, code = self._run_doctor(iso, capsys)
+        out, code = self._run_doctor(iso, capsys, setup_full=True)
         assert "All checks passed" in out
         assert "[FAIL]" not in out
         assert code == 0
@@ -150,6 +175,29 @@ class TestDoctor:
         assert "Disk space" in out
         assert code == 1
 
+    def test_config_with_token_fails(self, iso, capsys):
+        iso["config_file"].write_text('{"discord_token": "sk-abcdefghijklmnopqrstuvwxyz"}')
+        out, code = self._run_doctor(iso, capsys)
+        assert "[FAIL] config.json no plain text secrets" in out
+        assert code == 1
+
+    def test_gitignore_check(self, iso, capsys):
+        iso["config_file"].write_text('{"bot":{}}')
+        # No .gitignore → FAIL
+        out, code = self._run_doctor(iso, capsys)
+        assert "[FAIL] .gitignore" in out
+        assert code == 1
+
+    def test_ollama_check(self, iso, capsys):
+        iso["config_file"].write_text('{"bot":{}}')
+        out, code = self._run_doctor(iso, capsys, setup_full=True)
+        assert "Ollama reachable" in out
+
+    def test_claude_functional_check(self, iso, capsys):
+        iso["config_file"].write_text('{"bot":{}}')
+        out, code = self._run_doctor(iso, capsys, setup_full=True)
+        assert "Claude CLI functional" in out
+
 
 # ---------------------------------------------------------------------------
 # cmd_restart