[BUG] Auto-generated Qdrant/FAISS collection names contain ':' and crash on Windows (local mode unusable)

Bug description

On Windows, the auto-generated collection names in QdrantStorage and FaissStorage contain : (and .) characters from datetime.now().isoformat(). Because both storages use the generated name as a local filesystem path component, simply instantiating them with default arguments crashes on Windows:

• QdrantStorage(vector_dim=4, path=<dir>) → OSError: [WinError 123] The filename, directory name, or volume label syntax is incorrect: '<dir>\collection\2026-09-14T03:25:34.181072'
• FaissStorage(vector_dim=4, storage_path=<dir>) → RuntimeError: Error in __cdecl faiss::FileIOWriter::FileIOWriter(const char *) ... could not open C:\Users as soon as the index is persisted.

Root cause

QdrantStorage._generate_collection_name() returns datetime.now().isoformat() verbatim (camel/storages/vectordb_storages/qdrant.py:241), and FaissStorage._generate_collection_name() returns f"faiss_index_{datetime.now().isoformat()}" (camel/storages/vectordb_storages/faiss.py:123).

• Qdrant's local mode creates a directory <path>/collection/<collection_name>, and : is illegal in Windows path components.
• FaissStorage._get_index_path() joins storage_path with <collection_name>.index, hitting the same restriction.

Other storages in the same package already avoid this: chroma.py sanitizes with .replace(':', '-').replace('.', '-'), and milvus.py / tidb.py / weaviate.py strip non-alphanumeric characters with a regex. Only qdrant and faiss still emit raw ISO timestamps.

Reproduction (Windows)

import tempfile
from camel.storages.vectordb_storages import QdrantStorage, FaissStorage

# Qdrant local mode: crashes at instantiation
QdrantStorage(vector_dim=4, path=tempfile.mkdtemp())
# OSError: [WinError 123] ... 'C:\...\collection\2026-09-14T03:25:34.181072'

# FAISS with a storage path: crashes when the index is written
fs = FaissStorage(vector_dim=4, storage_path=tempfile.mkdtemp())
fs.add([VectorRecord(vector=[0.1, 0.2, 0.3, 0.4])])
# RuntimeError: ... could not open C:\Users\...

The bug is also visible in the existing test suite: on Windows, test/storages/vector_storages/test_all_vectordbs.py::test_vector_storage[qdrant:local] and test_get_payload_by_vector[qdrant:local] error at fixture setup with WinError 123, and test/memories/test_vector_db_memory.py errors the same way. (CI is ubuntu-only, so this is currently not covered.)

A related test-side issue: once setup succeeds, the qdrant:local fixture still fails at teardown on Windows, because shutil.rmtree(tmpdir) runs while the local Qdrant client still holds open file handles. The fixture never calls storage.close_client().

Proposed fix

1. Sanitize the generated names in qdrant.py and faiss.py with .replace(':', '-').replace('.', '-'), following the existing chroma.py precedent.
2. Call storage.close_client() in the qdrant:local test fixture before shutil.rmtree.
3. Add a regression test asserting that auto-generated collection names contain no Windows-illegal path characters (<>:"/\|?*).

I'm happy to open a PR with this fix.

Environment

• camel-ai: 0.2.91a7 (master @ 8c791b7)
• Python: 3.10.20
• OS: Windows 11 (10.0.26200)