fix(self-improvement-loop): bump background-review budget to 16 and suppress status leaks (#19710)

The background memory/skill review fork had two user-visible issues:

1. max_iterations=8 was too tight for multi-step reviews. A review that
   needs to skill_view one or two candidate skills, add a memory entry,
   and patch a skill routinely blew the budget — surfacing an 'Iteration
   budget exhausted (8/8)' warning to the user and leaving the review
   half-finished.

2. Mid-review lifecycle messages leaked into the user's terminal past the
   existing quiet_mode + redirect_stdout/stderr guards. _emit_status and
   _emit_warning route through _vprint(force=True) -> _print_fn /
   status_callback, which bypass sys.stdout entirely. The stdout redirect
   only catches raw print() calls.

Changes:
- Bump the review fork's max_iterations from 8 to 16.
- Set review_agent.suppress_status_output = True on the fork. This
  short-circuits _vprint unconditionally so _emit_status/_emit_warning
  emissions (iteration-budget warnings, rate-limit retries, compression
  messages) never reach the user. The only user-visible output remains
  the compact final summary line ('💾 Self-improvement review: ...')
  which is printed via self._safe_print on the *main* agent (outside
  the fork's redirect/suppress scope).

Summarizer filter is already correct — _summarize_background_review_actions
only surfaces tool calls with data.get('success') is truthy, so failed
attempts and reasoning text never reach the summary line.

run_agent.py

@@ -3611,7 +3611,7 @@ class AIAgent:
                     _parent_runtime = self._current_main_runtime()
                     review_agent = AIAgent(
                         model=self.model,
-                        max_iterations=8,
+                        max_iterations=16,
                         quiet_mode=True,
                         platform=self.platform,
                         provider=self.provider,
@@ -3629,6 +3629,14 @@ class AIAgent:
                     review_agent._user_profile_enabled = self._user_profile_enabled
                     review_agent._memory_nudge_interval = 0
                     review_agent._skill_nudge_interval = 0
+                    # Suppress all status/warning emits from the fork so the
+                    # user only sees the final successful-action summary.
+                    # Without this, mid-review "Iteration budget exhausted",
+                    # rate-limit retries, compression warnings, and other
+                    # lifecycle messages bubble up through _emit_status ->
+                    # _vprint and leak past the stdout redirect (they go via
+                    # _print_fn/status_callback, which bypass sys.stdout).
+                    review_agent.suppress_status_output = True
 
                     review_agent.run_conversation(
                         user_message=prompt,