feat(enrichers): web_search DuckDuckGo + tests pytest de los 5 enrichers

Anade enricher web_search aplicable a nodos text/Concept/Topic. Hace
POST a html.duckduckgo.com con la query del nodo, parsea resultados
con HTMLParser stdlib, decodifica el redirect uddg= y crea N nodos
Url con relacion SEARCH_RESULT_OF apuntando al nodo origen.

Encadenable: tras web_search, fetch_webpage sobre cada Url completa
el pipeline search -> fetch -> extract.

Defensa contra ops_db_path mal resuelto: normaliza backslashes,
resuelve relativo contra app_dir, valida que la tabla entities
exista antes de tocar nada (exit codes 7/8/9 con JSON resumen).

Tests pytest (16/16 verde): conftest con operations.db temp +
schema minimo, stub de requests via PYTHONPATH para mockear red.
Cubre los 5 enrichers (extract_domain, fetch_webpage, extract_links,
extract_text_entities, web_search) + sanity check de manifests.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/test_manifests.py

@@ -0,0 +1,72 @@
+"""Sanity check de los manifests YAML de todos los enrichers.
+
+Confirma que el set actual cubre los tipos esperados y que cada manifest
+tiene los campos que `enrichers.cpp` necesita parsear (id, applies_to).
+"""
+from __future__ import annotations
+
+from pathlib import Path
+
+from conftest import ENRICHERS_DIR
+
+
+EXPECTED_IDS = {
+    "extract_domain",
+    "extract_links",
+    "extract_text_entities",
+    "fetch_webpage",
+    "web_search",
+}
+
+
+def _parse_simple_yaml(text: str) -> dict:
+    """Parser ad-hoc que replica lo que hace enrichers.cpp."""
+    out: dict = {}
+    in_skip = False
+    for raw in text.splitlines():
+        line = raw.rstrip("\r")
+        s = line.strip()
+        if not s or s.startswith("#"):
+            continue
+        indented = line and line[0].isspace()
+        if not indented:
+            in_skip = False
+        if in_skip:
+            continue
+        if ":" not in s:
+            continue
+        key, _, val = s.partition(":")
+        key = key.strip()
+        val = val.strip()
+        if val and val[0] in ('"', "'") and val[-1] == val[0]:
+            val = val[1:-1]
+        if key == "params" and not val:
+            in_skip = True
+        out[key] = val
+    return out
+
+
+def test_all_expected_enrichers_present():
+    found = {p.name for p in ENRICHERS_DIR.iterdir() if p.is_dir()}
+    missing = EXPECTED_IDS - found
+    assert not missing, f"faltan enrichers: {missing}"
+
+
+def test_each_manifest_has_required_fields():
+    for d in ENRICHERS_DIR.iterdir():
+        if not d.is_dir():
+            continue
+        manifest = d / "manifest.yaml"
+        runpy    = d / "run.py"
+        assert manifest.exists(), f"falta manifest: {d.name}"
+        assert runpy.exists(),    f"falta run.py:  {d.name}"
+        m = _parse_simple_yaml(manifest.read_text(encoding="utf-8"))
+        assert m.get("id") == d.name, f"id no coincide con dir: {d.name}"
+        assert m.get("applies_to"), f"sin applies_to: {d.name}"
+        assert m.get("description"), f"sin description: {d.name}"
+
+
+def test_web_search_applies_to_text():
+    m = _parse_simple_yaml(
+        (ENRICHERS_DIR / "web_search" / "manifest.yaml").read_text())
+    assert "text" in m["applies_to"].lower()