test(agent): cover image domain in tool-RAG classifier

Verifies image-generation/edit phrasings resolve to the new `images`
domain (not low_signal), that the domain seeds generate_image/edit_image,
that it has a matching _DOMAIN_RULES pack, and that ordinary prompts are
not misclassified as image requests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: nsgds

tests/test_tool_rag_image_domain.py

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+"""Regression: the agent tool-RAG domain classifier had no image/media domain,
+so image-generation requests matched no domain, were flagged low_signal, and had
+tool retrieval SKIPPED entirely — the model only received ALWAYS_AVAILABLE tools
+(manage_memory, ask_user, update_plan) and never `generate_image`/`edit_image`,
+so it could not generate images (and tended to loop on manage_memory).
+
+Root cause: `_classify_agent_request` in src/agent_loop.py sets
+`low_signal = not continuation and not domains`; with no `images` domain, prompts
+like "generate two images of X" matched nothing -> low_signal -> retrieval skipped.
+
+The classifier is deterministic string matching (no embeddings / no DB), so it
+can be exercised directly.
+"""
+
+from src.agent_loop import (
+    _classify_agent_request,
+    _DOMAIN_TOOL_MAP,
+    _DOMAIN_RULES,
+    _domain_rules_for_tools,
+)
+
+
+def _classify(text):
+    return _classify_agent_request([{"role": "user", "content": text}], text)
+
+
+def test_image_generation_requests_get_image_domain():
+    """Image-generation phrasings must match the `images` domain and NOT be
+    treated as low-signal (which would skip tool retrieval)."""
+    prompts = [
+        "generate two images of this character: one action pose, one relaxed",
+        "draw me a picture of a cat",
+        "make an illustration of a spaceship",
+        "create an image of a sunset over mountains",
+        "design a logo for my coffee shop",
+    ]
+    for p in prompts:
+        intent = _classify(p)
+        assert "images" in intent["domains"], f"expected images domain for: {p!r}"
+        assert intent["low_signal"] is False, f"must not be low_signal: {p!r}"
+
+
+def test_image_edit_requests_get_image_domain():
+    """Edit/upscale/background phrasings also resolve to the image domain."""
+    for p in ("upscale image 5", "remove the background from this photo", "inpaint the selected area"):
+        intent = _classify(p)
+        assert "images" in intent["domains"], f"expected images domain for: {p!r}"
+
+
+def test_image_domain_seeds_generate_and_edit_image():
+    """The domain must seed the actual image tools so they are offered even when
+    semantic retrieval misses."""
+    assert _DOMAIN_TOOL_MAP["images"] == {"generate_image", "edit_image"}
+
+
+def test_image_domain_has_a_rule_pack():
+    """Every domain in _DOMAIN_TOOL_MAP needs a matching _DOMAIN_RULES entry,
+    otherwise _domain_rules_for_tools raises KeyError when the tools are selected."""
+    assert "images" in _DOMAIN_RULES
+    rules = _domain_rules_for_tools({"generate_image"})
+    assert any("Image rules" in r for r in rules)
+
+
+def test_non_image_requests_do_not_match_image_domain():
+    """Guard against over-triggering: ordinary prompts must not be flagged image."""
+    assert "images" not in _classify("what is the capital of France")["domains"]
+    assert "images" not in _classify("reply to the latest email in my inbox")["domains"]