fix(filters): mark truncated fallback output

[YOMXXX]

Summary

• add visible recovery hints when rtk git log reaches RTK-injected default caps
• use parser passthrough truncation markers for ruff, ESLint, Pylint, and golangci-lint JSON parse fallbacks
• add regression tests for hidden truncation in git log caps and parse-fail fallback paths

Fixes #2204

Verification

• cargo +1.93.0 fmt --check
• git diff --check
• cargo +1.93.0 test parse_failure_marks_truncation -- --nocapture
• cargo +1.93.0 test filter_log_output -- --nocapture
• cargo +1.93.0 clippy --all-targets
• cargo +1.93.0 test --all -- --skip small_grep_not_worse_than_plain