merge: integrate main into feat/v3-pipeline + port AsyncMemory to v3

Merge 190 commits from main including:
- limit→top_k rename across all vector store APIs
- custom_fact_extraction_prompt→custom_instructions rename
- enable_graph flag removal (use self.graph truthiness)
- US/Pacific→timezone.utc normalization
- 18 Category A bug fixes (partial updates, graph cleanup on delete,
  telemetry gating, metadata mutation prevention, filter operator
  merging, delete timestamps, actor_id preservation, etc.)

Conflict resolutions:
- openai.py: merged _pass_dimensions_to_api with embed_batch
- milvus.py: merged partial-update logic with BM25 text field
- qdrant.py: took main's enhanced _create_filter, merged BM25
  sparse vectors with partial-update endpoints
- test_main.py: adopted main's test structure, removed obsolete
  test_custom_prompts, kept hybrid search over-fetch assertion

AsyncMemory v3 port (full parity):
- Rewrote AsyncMemory._add_to_vector_store with the same 8-phase
  batch pipeline as sync Memory (single LLM call, batch embed,
  hash dedup, batch persist, batch entity linking, message saving)
- All blocking calls wrapped in await asyncio.to_thread()
- Moved _build_session_scope to module level for shared access

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

README.md

@@ -15,8 +15,6 @@
   <a href="https://mem0.dev/DiG">Join Discord</a>
   ·
   <a href="https://mem0.dev/demo">Demo</a>
-  ·
-  <a href="https://mem0.dev/openmemory">OpenMemory</a>
 </p>
 
 <p align="center">
@@ -102,6 +100,20 @@ Install sdk via npm:
 npm install mem0ai
 ```
 
+### CLI
+
+Manage memories from your terminal:
+
+```bash
+npm install -g @mem0/cli   # or: pip install mem0-cli
+
+mem0 init
+mem0 add "Prefers dark mode and vim keybindings" --user-id alice
+mem0 search "What does Alice prefer?" --user-id alice
+```
+
+See the [CLI documentation](https://docs.mem0.ai/platform/cli) for the full command reference.
+
 ### Basic Usage
 
 Mem0 requires an LLM to function, with `gpt-4.1-nano-2025-04-14` from OpenAI as the default. However, it supports a variety of LLMs; for details, refer to our [Supported LLMs documentation](https://docs.mem0.ai/components/llms/overview).
@@ -159,7 +171,7 @@ For detailed integration steps, see the [Quickstart](https://docs.mem0.ai/quicks
 ## 📚 Documentation & Support
 
 - Full docs: https://docs.mem0.ai
-- Community: [Discord](https://mem0.dev/DiG) · [Twitter](https://x.com/mem0ai)
+- Community: [Discord](https://mem0.dev/DiG) · [X (formerly Twitter)](https://x.com/mem0ai)
 - Contact: founders@mem0.ai
 
 ## Citation
@@ -177,4 +189,4 @@ We now have a paper you can cite:
 
 ## ⚖️ License
 
-Apache 2.0 — see the [LICENSE](https://github.com/mem0ai/mem0/blob/main/LICENSE) file for details.
+Apache 2.0 — see the [LICENSE](https://github.com/mem0ai/mem0/blob/main/LICENSE) file for details.