feat(debug): include desktop.log in hermes debug share / /debug / hermes logs (#38203)

The Electron desktop app writes boot failures, backend spawn output, and
Python tracebacks to HERMES_HOME/logs/desktop.log, but debug-share only
captured agent/errors/gateway — so desktop boot issues never made it into
shared debug reports.

- logs.py: register desktop -> desktop.log (enables 'hermes logs desktop')
- debug.py: capture desktop snapshot, add to summary report, upload full
  desktop.log in 'share', update privacy notice
- gateway /debug inherits the desktop tail via collect_debug_report()
- main.py + docs: help text and log-name table (also adds missing gui row)
- tests: desktop seed in fixture, new report test, three_pastes -> four_pastes

tests/hermes_cli/test_debug.py

@@ -31,6 +31,9 @@ def hermes_home(tmp_path, monkeypatch):
     (logs_dir / "gateway.log").write_text(
         "2026-04-12 17:00:10 INFO gateway.run: started\n"
     )
+    (logs_dir / "desktop.log").write_text(
+        "2026-04-12 17:00:15 INFO desktop: backend spawned\n"
+    )
 
     return home
 
@@ -451,6 +454,15 @@ class TestCollectDebugReport:
 
         assert "--- gateway.log" in report
 
+    def test_report_includes_desktop_log(self, hermes_home):
+        from hermes_cli.debug import collect_debug_report
+
+        with patch("hermes_cli.dump.run_dump"):
+            report = collect_debug_report(log_lines=50)
+
+        assert "--- desktop.log" in report
+        assert "backend spawned" in report
+
     def test_missing_logs_handled(self, tmp_path, monkeypatch):
         home = tmp_path / ".hermes"
         home.mkdir()
@@ -526,8 +538,8 @@ class TestRunDebugShare:
         assert "FULL agent.log" in out
         assert "FULL gateway.log" in out
 
-    def test_share_uploads_three_pastes(self, hermes_home, capsys):
-        """Successful share uploads report + agent.log + gateway.log."""
+    def test_share_uploads_four_pastes(self, hermes_home, capsys):
+        """Successful share uploads report + agent.log + gateway.log + desktop.log."""
         from hermes_cli.debug import run_debug_share
 
         args = MagicMock()
@@ -549,14 +561,16 @@ class TestRunDebugShare:
             run_debug_share(args)
 
         out = capsys.readouterr().out
-        # Should have 3 uploads: report, agent.log, gateway.log
-        assert call_count[0] == 3
+        # Should have 4 uploads: report, agent.log, gateway.log, desktop.log
+        assert call_count[0] == 4
         assert "paste.rs/paste1" in out  # Report
         assert "paste.rs/paste2" in out  # agent.log
         assert "paste.rs/paste3" in out  # gateway.log
+        assert "paste.rs/paste4" in out  # desktop.log
         assert "Report" in out
         assert "agent.log" in out
         assert "gateway.log" in out
+        assert "desktop.log" in out
 
         # Each log paste should start with the dump header
         agent_paste = uploaded_content[1]
@@ -565,6 +579,9 @@ class TestRunDebugShare:
         gateway_paste = uploaded_content[2]
         assert "--- hermes dump ---" in gateway_paste
         assert "--- full gateway.log ---" in gateway_paste
+        desktop_paste = uploaded_content[3]
+        assert "--- hermes dump ---" in desktop_paste
+        assert "--- full desktop.log ---" in desktop_paste
 
     def test_share_keeps_report_and_full_log_on_same_snapshot(self, hermes_home, capsys):
         """A mid-run rotation must not make full agent.log older than the report."""