fix: handle multimodal content in think scrubber

[rafasouzaramos-a11y]

Summary

• normalize OpenAI-style multimodal content arrays to visible text before regex scrubbing
• ignore image/non-text blocks in the display-text helper
• cover text/input_text/output_text, string parts, image-only content, and think tags

Reproduction

A Telegram user message containing native image content is stored as a list. _interim_assistant_visible_text() passes that list to strip_think_blocks(), which called re.sub() directly and raised TypeError: expected string or bytes-like object, got list. The outer conversation loop retried repeatedly.

Verification

• pytest tests/run_agent/test_run_agent.py::TestStripThinkBlocks -q → 30 passed
• ruff check agent/agent_runtime_helpers.py tests/run_agent/test_run_agent.py → passed
• live Telegram image → follow-up tool call completed with no new TypeError

[alt-glitch]

This was generated by AI during triage.

Related to closed-unmerged #66341, which included an interim-text coercion alongside separate no-retry and documentation work. This focused live helper repair remains an active implementation; #26504 is a distinct API-server content-normalization path.

[teknium1]

Thanks for the focused reproduction and coverage.

Automated hermes-sweeper review found this behavior is already implemented on current main:

• agent/agent_runtime_helpers.py:685-707 normalizes list and dict content before the regex scrubber; list handling excludes thinking/reasoning blocks and preserves visible text.
• run_agent.py:4819-4831 routes interim stored-message content through that shared helper.
• tests/run_agent/test_run_agent.py:448-480 already covers block-list, dict, thinking-only, and empty-list content.
• Commit 296494db0ee99f1cd9e384b2083e7a60aeb833ef (fix: stop infinite loop when assistant content is a block list) is an ancestor of current main; the related broader repair was also salvaged in merged PR fix: handle multimodal content in interim text and avoid retrying local processing errors #66945.

Closing as implemented on main.