Add CAJAL scientific paper agent template (#14641)

### What problem does this PR solve?

Closes https://github.com/infiniflow/ragflow/issues/14571.

Adds CAJAL as a first-class local scientific-writing option in RAGFlow:

- registers `agnuxo/cajal-4b-p2pclaw` as a known Ollama chat model with
a 32K context setting
- adds a built-in “CAJAL scientific paper agent” template under the
existing agent template catalog
- preconfigures the agent for grounded scientific writing: retrieval
first, citation traceability, LaTeX-ready output, and explicit
limitations when evidence is missing
- adds unit coverage to ensure the template normalizes through RAGFlow’s
production template loader, keeps graph form data in sync, and exposes
the Ollama model option

Behavior/evidence gathered for the requested model:

- Hugging Face model metadata for `Agnuxo/CAJAL-4B-P2PCLAW` reports
`pipeline_tag=text-generation` and tags including `gguf`, `llama.cpp`,
`vllm`, `scientific-research`, `papers`, `academic-writing`, `latex`,
and `license:apache-2.0`.
- The model card documents CAJAL as a 4B scientific paper generation
model with 32K context, local inference, LaTeX/citation specialization,
and CPU-only support around 5 tok/s on Ryzen 7 5800X.
- Local CPU generation could not be completed on this machine because
the advertised Ollama model name is not currently resolvable from
Ollama’s registry: both
`https://registry.ollama.ai/v2/agnuxo/cajal-4b-p2pclaw/manifests/latest`
and
`https://registry.ollama.ai/v2/library/agnuxo/cajal-4b-p2pclaw/manifests/latest`
returned `404 Not Found`; the Hugging Face repo tree currently exposes
an 8.4 GB `model.safetensors` but no GGUF artifact in `main`. The
template therefore targets the documented Ollama model name for users
who have the local CAJAL deployment/model file available.

Verification run locally:

```bash
python3 -m pytest test/test_cajal_template_unit.py -q
# 3 passed in 0.34s

python3 - <<'PY'
import json, glob
for f in sorted(glob.glob('agent/templates/*.json') + ['conf/llm_factories.json']):
    with open(f, encoding='utf-8') as fp: json.load(fp)
print('json_ok')
PY
# json_ok

python3 -m ruff check test/test_cajal_template_unit.py
# All checks passed!

git diff --check
```

`uv run pytest
test/testcases/test_web_api/test_agent_app/test_cajal_template_unit.py
-q` was also attempted first, but dependency setup failed before test
collection while building `ormsgpack==1.5.0` from uv with a package
metadata parse error. Clearing uv’s `ormsgpack` cache and retrying
reproduced the same build failure, so the focused unit test was run with
the system Python environment instead.

### Type of change

- [ ] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):

---------

Co-authored-by: sxxtony <sxxtony@users.noreply.github.com>
Co-authored-by: yzc <yzc@users.noreply.github.com>
Co-authored-by: Zhichang Yu <yuzhichang@gmail.com>

conf/llm_factories.json

@@ -1759,8 +1759,16 @@
             "logo": "",
             "tags": "LLM,TEXT EMBEDDING,SPEECH2TEXT,MODERATION",
             "status": "1",
-            "rank": "988",
-            "llm": []
+            "rank": "830",
+            "llm": [
+                {
+                    "llm_name": "agnuxo/cajal-4b-p2pclaw",
+                    "tags": "LLM,CHAT,32K,SCIENTIFIC_WRITING",
+                    "max_tokens": 32768,
+                    "model_type": "chat",
+                    "is_tools": false
+                }
+            ]
         },
         {
             "name": "ModelScope",