fix(vision): read max_tokens from auxiliary.vision config instead of hardcoded 2000

[adikpb]

Problem

vision_analyze and browser_vision both return truncated responses when analyzing complex images. The auxiliary vision model is called with a hardcoded max_tokens: 2000 cap, so descriptions of complex screenshots get cut off mid-sentence at exactly 2000 tokens.

Root cause — two files, same pattern

File	Line	Before
tools/vision_tools.py	1249	"max_tokens": 2000
tools/browser_tool.py	4328	"max_tokens": 2000

Both correctly read timeout and temperature from auxiliary.vision config, but skip max_tokens entirely — so there is no way to raise it without editing source.

Fix

In both files, add config reading for max_tokens right after the temperature block (which already reads timeout and temp from config), and use the configured value with a fallback to 2000:

_vmt = _vision_cfg.get("max_tokens")
if _vmt is not None:
    vision_max_tokens = int(_vmt)
else:
    vision_max_tokens = 2000

Then replace "max_tokens": 2000 → "max_tokens": vision_max_tokens.

Users can now configure it in config.yaml:

auxiliary:
  vision:
    max_tokens: 8000

Related issues/PRs

• Closes Default vision pre-process prompt generates overly long descriptions (~2000 chars), significantly slowing down image-bearing requests on local models #10809 (OPEN) — root issue, hardcoded max_tokens=2000 in vision_tools.py
• Closes [Bug/Enhancement] Hardcoded max_tokens and overly verbose prompt in vision_tools.py causes severe latency for reasoning models #29590 (OPEN) — explicitly requests reading auxiliary.vision.max_tokens from config
• PR fix(auxiliary): stop capping output with max_tokens by default (#34530) #34845 (merged) — fixed agent/auxiliary_client.py but NOT vision_tools.py or browser_tool.py (they build their own kwargs dicts manually)

Verification

All 139 vision-related tests pass:

tests/tools/test_vision_tools.py ............. 89 passed
tests/tools/test_vision_native_fast_path.py .. 10 passed
tests/run_agent/test_vision_aware_preprocessing.py ... 12 passed
tests/agent/test_vision_routing_31179.py .... 12 passed
tests/agent/test_vision_resolved_args.py .... 1 passed
Total: 139 passed

[adikpb]

Superseded by updated PR from current main