…shold

- Change error message from Chinese to English for upstream compatibility
- Increase default threshold from 3 to 5 to avoid false positives
  (legitimate retry scenarios exist, e.g. network jitter)
- Fix indentation bug in sequential execution path
- All 22 existing tests pass

Prevents the LLM from retrying different variations of a failing tool call.
When a tool returns errors/empty results N times consecutively (regardless of
argument changes), the counter triggers and forces a strategy change.

- Added _tool_failure_count dict and _tool_failure_threshold (5) in __init__
- Added _check_tool_failure() method to detect failures and update counter
- Added check calls in both concurrent and sequential execution paths
- Each tool has independent counter; success resets counter to 0

…_breaker_threshold from 5 to 3 - Reduces _tool_failure_threshold from 5 to 3 - Improves circuit breaker error message with specific suggestions - Helps stop tool-loop failures earlier

When a tool call fails repeatedly, the compression model is asked
for a suggestion. This gives the main model a fresh perspective
to break out of tool loops.

- Added _get_tool_suggestion() for retry threshold failures
- Added _get_consecutive_suggestion() for identical-call circuit breaker
- Suggestions are appended to the error message with a 💡 emoji
- Gracefully falls back if compression model is unavailable

When a tool call fails repeatedly, suggestions are provided even
without a compression model configured.

- Added _heuristic_suggestion() — pattern matching on error messages
- Added _heuristic_consecutive_suggestion() — 20+ tool-specific suggestions
- Compression model is tried first, then falls back to heuristics
- Works zero-config — no LLM needed for basic suggestions

Replaced complex pattern-matching heuristics with simple generic prompts.
- Removed _heuristic_suggestion() (8 pattern rules)
- Removed _heuristic_consecutive_suggestion() (20+ tool mappings)
- Fallback is now just a direct text suggestion
- Compression model still tries first for smarter suggestions
- Net: -90 lines of dead pattern logic