fix(cli): decouple tool_progress=verbose from global DEBUG logging (#31379)

PR #6a1aa420e coupled `display.tool_progress: verbose` (a per-tool display
toggle for full args / results / think blocks) to `self.verbose` — which
controls root-logger DEBUG level. Result: setting tool_progress: verbose
in config silently flipped every module in the process to DEBUG and
flooded the terminal with internal logging, far beyond just full tool
calls.

The two concepts are separate:
- `tool_progress_mode == 'verbose'` → display behavior (tool rendering)
- `self.verbose` → logging behavior (root logger → DEBUG, line 9795)

This change keeps PR #6a1aa420e's argparse.SUPPRESS / config-fallback
plumbing but severs the verbose-display → debug-logging link.

Changes:
- cli.py:2868 — `self.verbose` only follows explicit `verbose=` arg; no
  longer auto-True when tool_progress_mode == 'verbose'.
- cli.py:_toggle_verbose — slash-cycle through tool progress modes no
  longer flips `self.verbose` / `agent.verbose_logging` / `agent.quiet_mode`.
- cli.py:9355 — fix misleading label (drop 'and debug logs').
- tui_gateway/server.py:_make_agent — same decoupling on the TUI side
  (verbose_logging no longer derived from tool_progress_mode).
- tests/cli/test_tool_progress_scrollback.py — invert the test that
  asserted the broken coupling; add coverage for explicit `--verbose`
  still enabling DEBUG independent of tool_progress.

Live verified:
- tool_progress: verbose, no --verbose flag → 0 DEBUG/INFO log lines
- --verbose flag explicit → 32 DEBUG/INFO log lines (as expected)

tests/cli/test_tool_progress_scrollback.py

@@ -178,15 +178,30 @@ class TestToolProgressScrollback:
 
         mock_print.assert_not_called()
 
-    def test_verbose_mode_config_enables_cli_verbose_by_default(self):
-        """Config-only display.tool_progress=verbose should enable verbose output."""
+    def test_verbose_mode_config_does_not_enable_global_debug_logging(self):
+        """display.tool_progress=verbose controls TOOL-CALL DISPLAY ONLY.
+
+        It must NOT auto-flip self.verbose, which controls root-logger DEBUG
+        level for the entire process (every module spews to console).  PR
+        #6a1aa420e had coupled them, causing all debug logs to flood the
+        terminal whenever a user picked tool_progress: verbose for richer
+        per-tool rendering.
+        """
         cli = _make_cli(tool_progress="verbose")
 
         assert cli.tool_progress_mode == "verbose"
+        assert cli.verbose is False
+
+    def test_explicit_verbose_argument_wins_over_config(self):
+        """Explicit verbose=True from the CLI flag still enables DEBUG logging
+        regardless of tool_progress_mode."""
+        cli = _make_cli(tool_progress="off", verbose=True)
+
+        assert cli.tool_progress_mode == "off"
         assert cli.verbose is True
 
-    def test_explicit_non_verbose_argument_still_overrides_verbose_config(self):
-        """An explicit non-verbose value should keep overriding the config fallback."""
+    def test_explicit_non_verbose_argument_keeps_debug_logging_off(self):
+        """Explicit verbose=False overrides any default to enable DEBUG."""
         cli = _make_cli(tool_progress="verbose", verbose=False)
 
         assert cli.tool_progress_mode == "verbose"